Covered stent and stent system

Abstract

The covered stent comprises a main stent body and a branch stent body, the main stent body comprises a first side and a second side, the branch stent body is located on the first side, the main stent body comprises a first bare wave ring, a main wave ring and a main covering film, the main covering film is arranged on the main wave ring, and the first bare wave ring is connected with the near end of the main covering film. The first bare wave ring comprises a foldable part, a supporting part and an axial positioning part along 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; a circumferential unfolding part is arranged at the near end of the main body covering film and corresponds to the supporting part in the circumferential direction, so that the main body covering film does not limit unfolding of the supporting part. According to the covered stent provided by the invention, the circumferential unfolding part corresponding to the supporting part in the circumferential direction is arranged at the near end of the main body covered film, so that the main body covered film does not limit the unfolding of the supporting part in the circumferential direction, and the turnover part can be smoothly turned over.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and particularly relates to a covered stent and a stent system. Background Art

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

[0003] Traditional open surgical treatment of aortic diseases involving branch vessels for aortic aneurysm and aortic dissection has the disadvantages of large trauma, high mortality, long operation time, high incidence of postoperative complications, and high operation difficulty. Endovascular treatment has the characteristics of small trauma, few postoperative complications, short operation time, and low operation difficulty, and has gradually become the main method for treating aortic aneurysm and aortic dissection currently. By implanting a covered stent in the aorta, the vascular lesion is isolated outside the covered stent, and the blood flow is restricted to flow through the inside of the covered stent, thereby achieving the purpose of protecting the blood vessel. In a traditional aortic covered stent, generally along the main guide wire selected into the main lumen, after the main part is released, the branch on the aortic arch is selected through a prefabricated branch guide wire. Entanglement is likely to occur between the two guide wires. Moreover, when the branch guide wire selects the branch on the aortic arch, a snare on the upper limb approach is needed to snare the branch guide wire, so as to snare the branch guide wire into the branch on the aortic arch to complete the selection of the branch on the aortic arch. During the operation, the selection of the branch guide wire is difficult, which will prolong the operation time and increase the operation risk. Summary of the Invention

[0004] One technical problem solved by the present invention is how to set the main stent structure of a covered stent to reduce the number of guide wire selections on the premise of realizing the complete release of the main stent.

[0005] The present invention provides a covered stent, which includes a main stent and a branch stent. The main stent includes a first side and a second side, and the branch stent is located on the first side. The main stent includes a first bare wave ring, a main body wave ring, and a main body covering film. The main body covering film is arranged on the main body wave ring. The first bare wave ring is connected to the proximal end of the main body covering film. The first bare wave ring includes 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 body covering film is provided with a circumferential unfolding part, and the circumferential unfolding part corresponds to the setting of the support part in the circumferential direction, so that the main body covering film does not limit the unfolding of the support part.

[0006] In one embodiment, the circumferential deployment portion includes a notch recessed toward the distal end.

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

[0008] In one embodiment, the deployable length of the circumferential deployment portion is greater than or equal to the deployable length of the support portion at its corresponding position.

[0009] In one embodiment, the circumferential deployment portion includes an axial buffer portion to reduce the axial pulling of the main body film during the deployment of the circumferential deployment portion.

[0010] In one embodiment, the circumferential deployment portion includes a U-shaped notch recessed toward the distal end, and the axial buffer portion is the inclined bottom or flat bottom of the U-shaped notch.

[0011] In one embodiment, the proximal end portion of the main body film is in an inclined cut shape; the distal end portion of the second side of the first bare wave ring axially extends beyond the distal end portion of its first side, so that the distal end face of the first bare wave ring is in an inclined cut shape.

[0012] In one embodiment, the circumferential deployment portion includes a U-shaped notch recessed toward the distal end, the axial buffer portion is the inclined bottom of the U-shaped notch, and the inclined bottom is parallel to the distal end face of the first bare wave ring.

[0013] In one embodiment, the foldable portion includes a first waveform unit; the axial positioning portion includes a second waveform unit; the support portion includes a third waveform unit; the third waveform unit is respectively connected to the first waveform unit and the second waveform unit, 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.

[0014] The present invention also provides a stent system, characterized in that the stent system includes a delivery device and a covered stent as described above, the delivery device includes a sheath core assembly and a sheath tube, the sheath core assembly penetrates into the distal end of the main body stent and penetrates out of the branch stent, and the first bare wave ring is partially folded and loaded into the sheath tube as a whole.

[0015] In one embodiment, the delivery device further includes a guiding head. Define the axial distance from the proximal side connection point of the branch stent to the proximal end portion of the main body film as L5, and define the overall axial length of the branch stent as L6. Wherein, L5 and L6 satisfy: L6 > L5. In the stent system, the branch stent is closer to the guiding head axially than the proximal end of the main body stent.

[0016] In one embodiment, the free end of the foldable portion and the proximal end of the axial positioning portion do not interfere with each other, or the free end of the foldable portion presses against the outside of the axial positioning portion.

[0017] One technical effect of an embodiment of the present invention is to provide a covered stent. By providing a circumferential unfolding portion corresponding to the support portion in the circumferential direction at the proximal end of the main body covering film, the opening of the support portion is not restricted in the circumferential direction of the main body covering film, so that the foldable portion can be folded smoothly. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a side view of the covered stent provided in Embodiment 1 of the present invention;

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

[0020] Figure 3 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 is a schematic structural diagram of the covered stent provided in Embodiment 1 of the present invention;

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

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

[0024] Figure 6a is a schematic diagram of the first bare wave ring provided in Embodiment 1 of the present invention after the wave crest of the second waveform unit along the second side center line is axially cut and laid flat on a plane;

[0025] Figure 7 is Figure 1 the left view shown;

[0026] Figure 8 is a schematic connection diagram of the first wave valley and the main body covering film provided in Embodiment 1 of the present invention;

[0027] Figure 9 is a schematic connection diagram of the first wave valley and other embodiments of the main body covering film provided in Embodiment 1 of the present invention;

[0028] Figure 10 is Figure 9 a schematic diagram of the main body covering film when the first wave valley is omitted;

[0029] Figure 11Schematic diagram of the connection between the first trough and other embodiments of the main body film in Embodiment 1 of the present invention;

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

[0031] Figure 13 Schematic diagram of the film-covered stent in other embodiments provided in Embodiment 1 of the present invention;

[0032] Figure 14 Schematic diagram of the stent system of the branch stent including a semi-binding structure provided in Embodiment 1 of the present invention;

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

[0034] Figure 16 Schematic diagram of the process of loading the film-covered stent provided in Embodiment 1 of the present invention into the sheath tube (the first bare wave ring has not been constricted);

[0035] Figure 17 Schematic diagram of the process of loading the film-covered stent provided in Embodiment 1 of the present invention into the sheath tube (the foldable part is partially folded and waiting to be constricted);

[0036] Figure 18 Schematic diagram of the process of loading the film-covered stent provided in Embodiment 1 of the present invention into the sheath tube (the foldable part is folded, the support part is opened and radially compressed together with the axial positioning part, and the axial positioning part is constricted into the sheath tube);

[0037] Figure 19 Schematic diagram of the process of loading the film-covered stent provided in Embodiment 1 of the present invention into the sheath tube (the whole first bare wave ring is constricted into the sheath tube);

[0038] Figure 20 Schematic diagram of the process of loading the film-covered stent provided in Embodiment 1 of the present invention into the sheath tube (completing the loading of the film-covered stent into the sheath);

[0039] Figure 21 Schematic diagram of 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 invention;

[0040] Figure 22 Schematic diagram of the stent system provided in Embodiment 1 of the present invention being delivered along the guide wire to the left subclavian branch artery;

[0041] Figure 23 For Figure 22 Schematic diagram of retracting the sheath tube backward until the third imaging part is close to the first imaging part;

[0042] Figure 24 For relative Figure 23 Schematic diagram of continuously retracting the sheath tube to move the third imaging member away from the first imaging member and closer to the second imaging member;

[0043] Figure 25 For relative Figure 24 Schematic diagram of the foldable part being released from the sheath tube (the support part is to be released);

[0044] Figure 26 For relative Figure 25 Schematic diagram of the first bare wave loop being released from the sheath tube (the distal end of the main body bracket is to be released);

[0045] Figure 27 For relative Figure 26 Schematic diagram of the entire main body bracket being released from the sheath tube;

[0046] Figure 28 For relative Figure 27 The second bare wave loop of the branch bracket disengages from the sheath core and is completely released;

[0047] Figure 29 Schematic diagram of the proximal end of another covered stent provided in Embodiment 2 of the present invention;

[0048] Figure 30 For Figure 29 Schematic diagram of the structure of the first bare stent and the positioning wave loop in [[ ]];

[0049] Figure 31 For Figure 30 Schematic diagram of a combination method of the first bare stent and the positioning wave loop in [[ ]];

[0050] Figure 32 For Figure 30 Schematic diagram of another combination method of the first bare stent and the positioning wave loop in [[ ]];

[0051] Figure 33 Schematic diagram of the proximal end of yet another covered stent provided in Embodiment 2 of the present invention;

[0052] Figure 34 Schematic diagram of the proximal end of still another covered stent provided in Embodiment 2 of the present invention;

[0053] Figure 35 For Figure 34 Schematic diagram of the two second waveform units of the axial positioning portion of the first bare wave loop being axially cut open and laid flat on a plane in [[ ]];

[0054] Figure 36 Side view of the covered stent provided in Embodiment 3 of the present invention;

[0055] Figure 37 For Figure 37Enlarged view of the structure of the middle circumferential expansion part;

[0056] Figure 38 Side view of another covered stent provided in Embodiment 3 of the present invention;

[0057] Figure 39 is Figure 38 Enlarged view of the structure of the middle circumferential expansion part;

[0058] Figure 40 Side view of yet another covered stent provided in Embodiment 3 of the present invention;

[0059] Figure 41 is Figure 40 Enlarged view of the structure of the middle circumferential expansion part;

[0060] Figure 42 Side view of still another covered stent provided in Embodiment 3 of the present invention. Detailed implementation manners

[0061] For the convenience of understanding the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. The preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0062] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "inner", "outer", "left", "right" and similar expressions used herein are only for illustrative purposes and do not represent the only embodiments.

[0063] "Axial direction" generally refers to the length direction of the medical device when it is being delivered, and "radial direction" generally refers to the direction perpendicular to the "axial direction" of the medical device. Based on this principle, the "axial direction" and "radial direction" of any component of the medical device are defined. In addition, when elaborating on a lumen stent or a covered stent, the orientation can be defined according to the blood flow direction in the blood vessel. In the present invention, it is defined that the blood flow flows from the proximal end to the distal end of the stent. A waveform unit is defined as a single-period waveform including one wave crest and two wave rods, or a single-period waveform including one wave trough and two wave rods. In the field of interventional medical devices, generally for a delivery device for delivering a medical device into the human body or an animal body, the end closer to the operator is called the "proximal end", and the end farther from the operator is called the "distal end". Based on this principle, the "proximal end" and "distal end" of any component of the delivery device are defined.

[0064] Example 1

[0065] As Figures 1-31 shown, this embodiment provides a covered stent 100. The covered stent 100 includes a main stent 10 and a branch stent 20, as Figure 1 shown.

[0066] As Figures 1-6 shown, the main stent 10 is a tubular structure with openings at both ends, including a first bare coil 11, a main coil 12, and a main covering 13. The proximal part of the main covering 13 is its proximal end 131. The first bare coil 11 is connected to the proximal end of the main covering 13. In this embodiment, the distal end of the first bare coil is connected to the proximal end of the main covering and has the same inclination trend. Among them, the distal part of the first bare coil is its distal end (not shown in the figure, which can be analogized to the proximal end of the main covering). Among them, there are multiple main coils 12. The multiple main coils 12 are arranged axially and connected by the tubular main covering 13. The number of main coils 12 can be set from 1 to 30.

[0067] In this embodiment, the main coils 12 are arranged outside the main covering 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 is beneficial to preventing the main stent 10 from shifting or shortening relative to the inner wall of the blood vessel. In other embodiments, the main coils 12 can also be arranged inside the main covering 13, or part of the main coils 12 are arranged inside the main covering 13 and part are arranged outside the main covering 13, which is not limited here.

[0068] The main stent 10 includes a first side 101 and a second side 102. When it is defined that the covered stent 100 is in the implanted state and the branch stent 20 faces the side of the aortic branch, the first side 101 is the side of the main stent 10 close to the aortic branch, and the second side 102 is the side of the main stent 10 away from the aortic branch. The first side and the second side each occupy an arc of 180°, and the branch stent 20 can be arranged at the middle position of the arc of the first side 101.

[0069] As Figures 3-4 Combined Figure 6 and Figure 6aAs shown, the distal end of the first bare wave loop 11 includes a first distal end 11a located on the first side 101 and a second distal end 11b located on the second side 102. The first distal end 11a and the second distal end 11b are located on different radial cross-sections, so that the angle between the line connecting the first distal end 11a and the second distal end 11b of the first bare wave loop 11 and the axial line of the main body bracket 10 is an acute angle, thereby facilitating partial folding of the first bare wave loop 11; in this embodiment, the circumferential position of the first distal end 11a is deflected by no more than 20° relative to the circumferential position of the branch bracket, and the circumferential relative interval between the second distal end 11b and the first distal end 11a is in the range of 160° to 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 the end closest to the branch bracket 20 in the circumferential direction (the end connected to the main body bracket), and the second distal end 11b is the distal end of the axial positioning part 112 and the end farthest from the branch bracket 20 in the circumferential direction (the end connected to the main body bracket). In this embodiment, for the convenience of description, the waveform unit is a single-period waveform including one wave crest and two wave rods (the endpoints of the two wave rods far from the wave crest are the trough positions of the waveform unit), as Figure 6 shown, the first distal end 11a is the two symmetric trough ends of the first waveform unit 1111 in the middle of the foldable part 111, and the second distal end 11b is the two symmetric trough ends of the second waveform unit 1121 in the middle of the axial positioning part.

[0070] As Figures 1-6 shown, the first bare wave loop 11 is a nitinol ring composed of a plurality of waveform units similar to sine waves. The number of waveform units of the first bare wave loop 11 is 4 - 10; the wire diameter range of the first bare wave loop 11 is 0.3 mm to 0.45 mm; the wave height range of the waveform unit is 1 mm to 15 mm. The wave height H1 of the first waveform unit 1111 is taken as an example, and H1 is as Figure 3 shown, Figure 3 The dashed line in

[0071] In this embodiment, as Figure 1As shown, the distal end portion of the second side 102 of the first bare wave loop 11 axially extends beyond the distal end portion of its first side 101, making the distal end portion of the second side of the first bare wave loop 11 closer to the distal end of the main body bracket 10, so that the distal end face of the first bare wave loop 11 is in an inclined cut shape, and the proximal end portion of the first side of the main body film 13 axially extends beyond the proximal end portion of the second side of the main body film, making the proximal end portion of the first side of the main body film 13 closer to the proximal end of the first bare wave loop 11, so that the proximal end face of the main body film 11 is in an inclined cut shape. The proximal end face of the main body film 13 and the distal end face of the first bare wave loop 13 have the same inclination trend, which is convenient for the matching connection between the distal end portion of the first bare wave loop 11 and the proximal end portion of the main body film 11; or in other embodiments, the distal end portion of the first side of the first bare wave loop axially extends beyond the distal end portion of its second side, making the distal end portion of the first side of the first bare wave loop closer to the distal end of the main body bracket, so that the distal end face of the first bare wave loop is in an inclined cut shape. There is no limitation here, as long as the first distal end 11a and the second distal end 11b are located on different radial cross-sections.

[0072] As Figure 5 Combined Figures 2-3 As shown, the first bare wave loop 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 in the circumferential direction of the first side 101 and the axial line T2 passing through the midpoint F in the circumferential direction of the second side 102 form a projection plane S, as Figure 4 shown (in this embodiment, the branch bracket is located on the axial line where the midpoint in the circumferential direction of the first side is located); the connecting line of the end points of the projections of the first waveform unit 1111 and the second waveform unit 1121 on the projection plane S is in the shape of a parallelogram or a trapezoid, as Figure 3 shown, and the projection plane S is the plane where this figure is located. When the distal end portion of the second side 102 of the first bare wave loop 11 axially extends beyond the distal end portion of its first side 101, making the distal end portion of the second side 102 of the first bare wave loop 11 closer to the distal end of the main body bracket 10, the distal end point of the first side 101 located in the parallelogram or trapezoid is closer to the distal end of the main body bracket 10 than the proximal end point of the second side 102 located in the parallelogram or trapezoid. All radial cross-sections between the distal end point of the first side 101 and the proximal end point of the second side 102 can pass through the wave rods of each waveform unit of the foldable portion 111 and the axial positioning portion, so that more wave rods can be intercepted by this radial cross-section, enabling the first bare wave loop 11 to still maintain a certain radial support function under the inclined structure.

[0073] In this embodiment, the distal end portion of the second side of the first bare coil 11 axially extends beyond the distal end portion of its first side, such that the distal end face of the first bare coil 11 is of an inclined cut type, making the first distal end 11a of the first bare coil 11 closer to the proximal end of the first bare coil 11 than the second distal end 11b, as Figures 1-3 shown. Compared with the case where the distal end portion of the first side of the first bare coil axially extends beyond the distal end portion of its second side (the distal end portion of the first side of the first bare coil is closer to the distal end of the main body bracket), the arrangement of the first bare coil 11 in this embodiment, as Figure 18 combined with Figure 25 shown, enables the foldable portion 111 of the first bare coil 11 to be folded and compressed in the sheath 32 with its back facing the branch stent 20. And since the delivery device 30 is attached to the large curvature side (the side with branches on the aortic arch 800) of the aortic arch 800 portion, the delivery device 30 releases the first bare coil 11 while attached to the large curvature side of the blood vessel. When the first bare stent is partially released, only the foldable portion 111 is released from the sheath 32. At this time, the first bare stent as a whole is the same coil, with a part (the foldable portion 111) released from the sheath 32 and the other part (the axial positioning portion 112) still received in the sheath 32, causing the proximal end of the released foldable portion 111 to bend towards the lumen center of the covered stent 100; when the first bare coil 11 is in a natural state, the distal end portion of the second side of the first bare coil 11 axially extends beyond the distal end portion of its first side, making the distal end portion of the second side 102 of the first bare coil 11 closer to the distal end of the main body bracket 10 than the distal end portion of the first side 101; when only the foldable portion 111 is released, the released foldable portion 111 bends in the direction towards the lumen center of the main body bracket 10 with its back facing the large curvature side 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] As Figure 1As shown, the proximal end of the main body membrane 13 is of an oblique incision type. The proximal end of the first side of the main body membrane 13 axially extends beyond the proximal end of its second side, such that the proximal end of the first side 101 of the main body membrane 13 is farther from the distal end of the main body membrane 13 than the proximal end of the second side 102; alternatively, in other embodiments, the proximal end of the second side of the main body membrane axially extends beyond the proximal end of its first side. In this embodiment, the distal end face of the main body membrane 13 is of a flat mouth type, and the proximal end of the first side 101 of the main body membrane 13 axially extends beyond the proximal end of its second side 102, that is, the proximal end of the second side 102 of the main body membrane 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 membrane 13. When the proximal end of the main body stent 10 is placed in the aortic arch 800, the beak effect during the fitting of the second side 102 (the side away from the branch of the arch) to the vascular arch part can be improved. In this embodiment, the valleys at the distal end of the first bare wave ring 11 are in the same plane, and the distal shape of the first bare wave ring 11 corresponds to the proximal shape of the main body membrane 13, so as to facilitate connecting the valleys of the first bare wave ring 11 to the proximal end part of the main body membrane 13, as Figures 1-6 shown.

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

[0076] As Figure 7 shown, the foldable part 111, the support part 113, and the axial positioning part 112 in the first bare wave ring 11 are symmetrically arranged relative to the connection line T along the directions of the first side 101 and the second side 102. The direction of the connection line T is generally consistent with the extending direction of the branch stent 20 (generally consistent means: the included angle between the connection line T and the extending direction of the branch stent 20 is 0° to 10°). That is, from the first side 101 to the second side 102 of the first bare wave ring 11, both sides of the connection line T sequentially include the foldable part 111, the support part 113, and the axial positioning part 112, as Figure 7As shown, for convenient marking, two auxiliary dashed lines and the connecting line T are used to divide the circumferential direction of the covered stent 100 into six parts. The foldable part 111 here is symmetrically arranged relative to the connecting line T, which does not mean that the specific structures of the foldable parts 111 on both sides of the connecting line T are completely symmetric and identical, but rather that the corresponding positions on both sides of the connecting line T are the foldable parts 111; similarly, the supporting part 113 (axial positioning part 112) is symmetrically arranged relative to the connecting line T, which does not mean that the specific structures of the supporting parts 113 (axial positioning parts 112) on both sides of the connecting line T are completely symmetric and identical, but rather that the corresponding positions on both sides of the connecting line T are the supporting parts 113 (axial positioning parts 112), so as to facilitate the folding and compression of the first bare wave ring 11.

[0077] The foldable part 111 includes a first waveform unit 1111, the axial positioning part 112 includes a second waveform unit 1121, and the supporting part 113 includes a third waveform unit 1131; as Figures 2-3 Combined Figure 5 As shown, the third waveform unit 1131 is respectively connected to the first waveform unit 1111 and the second waveform unit 1121. The wave height of the third waveform unit 1131 is less than the wave height of the first waveform unit 1111, or / and the wave height of the third waveform unit 1131 is less than the wave height of the second waveform unit 1121. Here, the wave height refers to the vertical height from the wave peak of a waveform unit to the line connecting two wave valleys. The wave height of the third waveform unit 1131 is less than or equal to half of the smaller wave height of the first waveform unit 1111 and the second waveform unit 1121. The smaller wave height of the third waveform unit 1131 can prevent the span distance after the supporting part 113 expands from being too different from the natural span distance of the waveform when the first bare wave ring 11 is loaded into the sheath, which may cause inconvenience in folding the foldable part 111 with the film.

[0078] Define the length of the longer wave bar of the first waveform unit 1111 as L3, the length of the longer wave bar of the second waveform unit 1121 as L4, and the lumen radius of the main stent 10 as R. Then the sum of L3 and L4 satisfies: L3 + L4 ≤ 2R; in this embodiment, the wave height, wavelength of the first waveform unit 1111 and the second waveform unit 1121 are the same, the wave height of the third waveform unit 1131 is half of the wave height of the first waveform unit 1111, and the wave valleys of the first waveform unit 1111, the second waveform unit 1121 and the third waveform unit 1131 are on the same oblique section, as Figure 3 As shown, at the same time, the proximal end of the main covered film 13 is in an oblique incision shape, as Figure 1As shown, the inclination of the same diagonal cross-section where each wave trough of the first bare wave loop 11 is located relative to the axial direction is the same as the inclination of the proximal diagonal incision of the main body film 13 relative to the axial direction, facilitating the connection of each wave trough to the proximal end of the main body film 13. The length of the longer wave rod in the first waveform unit 1111 and the third waveform unit 1131 can be set to R. When the stent-graft 100 is in the loaded state, the foldable part 111 folded onto the support part 113 and the axially positioned part 112 compressed radially do not overlap axially, which can reduce the radial dimension in the compressed state and prevent interference between the axially positioned part 112 and the foldable part 111 during release.

[0079] Each wave trough of the first bare wave loop 11 is connected to the outer or inner side of the proximal end of the main body film 13, and there is no limitation here. In other embodiments, the inclination of the diagonal cross-section where the distal wave trough of the first bare wave loop 11 is located may also be different from the inclination of the proximal diagonal incision of the main body film 13, as long as it is satisfied that the first distal end 11a and the second distal end 11b of the first bare wave loop 11 are located on different radial cross-sections, facilitating the foldable part 111 of the first bare wave loop 11 to fold towards the distal end onto the support part 113. In other embodiments, the proximal end of the main body film 13 does not exceed one-third of the length of the first bare stent wave rod axially, so as to facilitate the film not to affect the folding of the first bare wave loop 11 and prevent excessive accumulation of the proximal film of the main body stent 10 after folding.

[0080] In this embodiment, the first bare wave loop 11 includes 8 waveform units, and the central angles corresponding to the arc lengths spanned by the two wave troughs of each waveform unit in the circumferential direction of the lumen of the main body stent 10 are basically the same, as Figures 5-7 shown, the foldable part 111 includes three first waveform units 1111 close to the first side 101, the axially positioned part 112 includes three second waveform units 1121 close to the second side 102, the support part 113 includes two third waveform units 1131 in the middle, and 1.5 first waveform units 1111 are located on both sides of the connection line T, 1.5 second waveform units 1121 are located on both sides of the connection line T, and one third waveform unit 1131 is located on both sides of the connection line T. When the stent-graft 100 is loaded into the sheath, the two wave rods (1131a, 1131b) of the third waveform unit 1131 of the support part 113 open with the connection 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 Figures 17-18 Combined with Figure 5As shown in the figure; the first waveform unit 1111 of the foldable part 111 is radially compressed, and at the same time, it folds as the third waveform unit 1131 of the support part 113 expands, and it folds approximately 180° axially; the second waveform unit 1121 of the axial positioning part 112 is radially compressed, and at the same time, it approaches the wave rod (1131b) of the adjacent support part 113. The axial positioning part 112 is only compressed radially, and the relative position in the axial direction remains basically unchanged;

[0081] As Figure 2 shown, the third waveform unit 1131 includes a first wave rod 1131a and a second wave rod 1131b. The range of the included angle α between the first wave rod 1131a and the second wave rod 1131b satisfies: 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 is not conducive to the first wave rod 1131a and the second wave rod 1131b of the third waveform unit 1131 moving away from each other with the vertex of the α angle as the fulcrum, increasing the difficulty of expanding and compressing the support part 113 into the sheath; the included angle α between the first wave rod 1131a and the second wave rod 1131b should not be too large either. If α is too large, when the first wave rod 1131a and the second wave rod 1131b move away from each other, the deformation of the support part 113 when it expands to nearly 180° (the state in the sheath tube 32) is small. When the sheath tube 32 is withdrawn to release the covered stent 100, the contribution of the elastic restoring force of the first wave rod 1131a and the second wave rod 1131b is small, which is not conducive to the covered film at the corresponding position of the support part 113 fitting the inner wall of the blood vessel; in other embodiments, the range of the included angle α between the first wave rod 1131a and the second wave rod 1131b that has a better effect satisfies: 77° ≤ α ≤ 89°. Define the included angle between the first wave rod 1131a and the wave rod on one side of the foldable part 111 as β, and the range of the included angle β satisfies: 25° ≤ β ≤ 73°. Among them, if the β angle is too large, when the foldable part 111 is released and the support part 113 is to be released (as Figure 25 shown), it is not conducive to the support part 113 returning towards the foldable part 111 (because the deformation amount of its included angle relative to the β angle in the natural state is small). In other embodiments, the range of the included angle β satisfies: 42° ≤ β ≤ 58°; define the included angle between the second wave rod 1131b and the wave rod on one side of the axial positioning part 112 as γ, and the range of the included angle γ satisfies: 52° ≤ γ ≤ 119°. Among them, if the γ angle is too small, it is not conducive to the radial return of the axial positioning part 112 (that is, 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 return of the axial positioning part 112 to move to the small bend side of the aortic arch 800 and adhere to the wall). In other embodiments, the range of the included angle γ satisfies: 73° ≤ γ ≤ 87°.

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

[0083] In this embodiment, as Figure 5 shown, the connection point of the distal end of the first corrugated rod 1131a and the foldable part 111 is the first connection point P, thereby forming the first trough 1131c of the support part 113, and the first trough 1131c is movably connected to the main body film 13; the connection point of the distal end of the second corrugated rod 1131b and the axial positioning part 112 is the second connection point, thereby forming the second trough 1131d of the support part 113, and the second trough 1131d is movably connected to the main body film 13 of the stent 100. Among them, the distal end of the first bare stent is located inside the main body film 13. When the first bare stent is in the natural state, define the position of the first trough 1131c inside the main body film 13 as the first axial limit position M, as Figure 8 shown, define the position of the second trough 1131d inside the main body film 13 as the second axial limit position (not shown in the figure). In this embodiment, in the first bare corrugated ring 11, the troughs other than 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; it is also possible that both the first trough 1131c and the second trough 1131d are fixedly connected to the main body film 13, and there is a surplus (fold) or notch in a part of the main body film 13 between the first trough 1131c and the second trough 1131d, without restricting the first corrugated rod 1131a and the second corrugated rod 1131b from moving away from each other.

[0084] As Figures 8-11 shown, the main body stent 10 further includes a non-fixed limiting member 15 located at the proximal end of the first trough 1131c, which is used to limit the first trough 1131c so that the first trough 1131c does not exceed the proximal end of the film, thereby having a supporting effect on the film. At the same time, during the opening process 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 as to facilitate the first corrugated rod 1131a and the second corrugated rod 1131b to move away from each other without involving the film.

[0085] In this embodiment, the non-fixed limiting member 15 is a movable limiting wire 151, and the limiting wire can be a polyester wire, a nitinol wire or a tantalum wire.

[0086] Define the wire diameter of the first bare wave loop 11 as d. The limiting wire bypasses the first wave valley 1131c and the proximal side of the main film covering 13, as Figure 8 shown, and the two ends of the limiting wire are sutured to the film covering, or one end passes through the film covering and is fixed to the other end, so that a gap Q is formed at the first axial limiting position M. The width of the gap Q extending towards the distal end from the first axial limiting position M is greater than or equal to 2d. When loading the film-covered stent 100, 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 within the gap Q; when releasing the film-covered stent 100, 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 wire 151 enables the first wave valley 1131c not to exceed the proximal end of the main film covering 13, and the first bare wave loop 11 still has an expanding and supporting effect on the proximal end of the main film covering 13 corresponding to the supporting part 113 in the circumferential direction.

[0087] In other embodiments, as Figures 9-10 shown, the limiting wire is fixed to the main film covering 13 at least at two places (which can be the two ends of the wire), forming a first fixing point 151a and a second fixing point 151b. The first fixing point 151a is located on the proximal side of the first axial limiting position M, and the second fixing point 151b is located on the distal side of the first axial limiting position M and is spaced from the first fixing point 151a, and the width of the gap Q formed between the two fixing points is greater than or equal to 2d. Among them, the first fixing point 151a and the second fixing point 151b are on the same axial line. In other embodiments, the first fixing point 151a and the second fixing point 151b may not be on the same axial line, and the second fixing point 151b is closer to the side of the second wave valley 1131d in the vertical axial direction relative to the first fixing point 151a, so that the extending direction (the connecting line direction of the two fixing points) of the gap Q formed by the limiting wire between the first fixing point 151a and the second fixing point 151b is inclined relative to the axial direction, and the inclined direction is opposite to the inclined direction of the first wave rod 1131a relative to the axial direction, which is more beneficial for the movement of the first wave rod 1131a relative to the main film covering 13 when loading into the sheath, so that when the first wave rod 1131a and the second wave rod 1131b move away from each other, it does not affect the film covering. And, when releasing the film-covered stent 100, due to the self-deformation of the supporting part 113 during loading (the included angle between the first wave rod 1131a and the second wave rod 1131b becomes larger) having a resilience force to return to the natural state, and the non-fixed limiting member 15 restricts the farthest position of the proximal end of the first wave valley 1131c, the first wave valley 1131c does not exceed the proximal end of the main film covering 13, and the first bare wave loop 11 still has an expanding and supporting effect on the proximal end of the main film covering 13 corresponding to the supporting part 113 in the circumferential direction.

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

[0089] As Figure 1 and Figure 4 combined Figure 12 shown, the branch stent 20 is located on the first side 101 of the main body stent 10, communicates with the inner part of the lumen of 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 loop 21, branch wave loops 22 and a branch membrane 23. The second bare wave loop 21 is connected to the branch membrane 23, and the second bare wave loop 21 is arranged at the end of the branch stent 20 far from the main body stent 10. There are multiple branch wave loops 22, and the multiple branch wave loops 22 are arranged at intervals and are connected by a tubular branch membrane 23. Among them, the branch stent 20 and the main body stent 10 can connect the branch wave loops 22 and the main body membrane 13 into a whole through the branch membrane, and the connection method can be connection methods such as suture and bonding. One end of the branch stent 20 far from the second bare wave loop 21 forms a connection part with the main body stent 10 along the circumferential direction of the branch stent 20. A circumferential imaging ring or imaging points are arranged at intervals along the circumferential direction at the circumferential connection part to mark the circumferential boundary of the branch opening, so as to facilitate identifying the position of the stent branch opening corresponding to the branch blood vessel.

[0091] In other embodiments, as Figures 13-15 shown, 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. There is also a transition section 27 between the extension section 25 and the connection section 24, and the outer diameter of the transition section 27 gradually increases from the connection section 24 to the extension section 25. A semi-restraint structure 26 is arranged on the branch stent 20, so that during the proximal release process of adjusting the main body stent 10, the branch stent 20 is in a semi-restrained state, and the diameter of the restrained branch stent is 40% - 75% of the diameter of the branch stent before restraint, so that the branch stent 20 can move axially in the branch, thus facilitating adjusting the fitting position of the connection between the proximal side of the branch stent 20 and the main body stent 10 and the blood vessel. When a branch small stent needs to be connected, the semi-restraint structure 26 can also not be arranged, and the outer diameter of the branch stent 20 can be set smaller, which is convenient for axially adjusting the position of the branch stent 20 after the sheath tube 32 is released. The outer diameter range is set between 6 mm and 20 mm, so that it does not stick to the inner wall of the branch blood vessel after release. Finally, a branch small stent is released through the guide wire 90 to fit the inner wall of the branch blood vessel.

[0092] As shown Figure 15 in the figure, the semi-restraint structure 26 includes a restraint wire 26a circumferentially arranged around the branch wave loop 22 and a plurality of wire buckles 26c fixed circumferentially on the branch wave loop 22. A limit buckle 26b is arranged at the end of the restraint wire 26a. Correspondingly, the conveying device 30 further includes a limit rod 33. During loading, the limit rod 33 axially penetrates through the limit buckles 26b at both ends of the restraint wire 26a along the branch bracket 20, thereby semi-restraining the branch bracket 20 and making the branch bracket 20 in a state of incomplete circumferential release. The limit rod 33 can be a metal guide wire 90 with good elastic memory and small surface roughness, such as a nitinol wire, whose physical properties meet the requirements and have good biocompatibility with the human body. A plurality of restraint wires 26a are arranged at intervals along the axial direction of the branch bracket 20. The circumferential angle covered by the restraint wire 26a on the circumference of the branch bracket 20 in the natural state is 180° - 270°, so as to control the change range of the branch bracket 20 from the semi-release state to the full-release state within a reasonable range; the restraint wire 26a can be a flexible wire with strong anti-tensile performance, such as a PTFE wire or a polyester suture, etc.

[0093] As shown Figure 12 in the figure, the axial distance from the proximal side connection point of the branch bracket 20 to the proximal end of the main body film 13 is defined as L5. Among them, L5 satisfies: 3mm ≤ L5 ≤ 16mm; when the proximal end face of the first bare wave loop 11 is not perpendicular to the axis of the covered stent 100, its proximal end face is an inclined plane, and the first bare wave loop is sutured to the main body film. When the foldable part is folded, the distance from the proximal side of the main body stent to the proximal side connection point of the branch bracket at this time is less than L5. The overall axial length of the branch bracket 20 along the axis of the branch bracket is defined as L6, and L6 satisfies: 3mm ≤ L6 ≤ 60mm; among them, L5 and L6 satisfy: L6 > L5; the branch wave loops of the branch bracket can be arranged at intervals along the axis of the branch bracket, or can be a support wave loop structure formed by hooking and weaving. The branch wave loop only needs to meet the performance of its support wave loop, and its specific structure is not limited here. When the guide wire 90 is selected into the supra-aortic branch, the sheath core assembly 31 needs to penetrate from the distal end of the main body stent 10 and pass through the branch bracket 20, so as to send the branch bracket 20 along the guide wire 90 into the branch. Setting L6 > L5 enables the foldable part of the first bare wave loop of the covered stent to be folded to the support part, the wave rods of the support part to open, and together with the axial positioning part to be compressed in the sheath tube to form a stent system. During the release process of this stent system, it is convenient for the proximal part of the branch bracket to expose from the end of the sheath tube away from the operating handle earlier than the proximal part of the main body stent, so as to facilitate adjusting the proximal end of the main body stent 10 in the main cavity of the aortic arch and prevent the proximal end of the main body stent 10 from being released in the supra-aortic branch earlier than the branch bracket 20.

[0094] In this embodiment, a first developer 16 is disposed at a position on the first side of the main body film 13 where it is connected to the foldable portion 111 and closest to the axial line T1 of the midpoint E in the circumferential direction of the first side 101, for identifying the proximal end of the main body stent 10 after the foldable portion 111 is folded. The first developer 16 can be a developer wire sutured to the main body film 13, and can be in the shape of an 8 or a 0. The film-covered stent 100 further includes a second developer 17, which is located at the proximal end of the foldable portion 111 and can be used to indicate the specific position of the end of the foldable portion 111 after it is folded and compressed into the sheath 32 (when the sheath 32 passes over this end position, the foldable portion 111 is released from the sheath 32). The second developer 17 can be a developer wire wound around the proximal peak of the first corrugated unit 1111; alternatively, the second developer can not be provided at the proximal end of the foldable portion, and the wire diameter of the first bare wave loop is made larger than that of the positioning wave loop 14, and the contour of the foldable portion can also be made clearly visible under fluoroscopy, different from the contour of the positioning wave loop, so that its position in the sheath can be directly distinguished in the folded state.

[0095] This embodiment also provides a stent system, as Figures 16-28 shown. The stent system includes a delivery device 30 and the film-covered stent 100 as described above. The delivery device 30 includes a sheath core assembly 31 and a sheath 32. The sheath core assembly 31 further includes a guide head 311. The sheath core assembly 31 penetrates into the main body stent 10 from the distal end and exits from the branch stent 20. A part of the first bare wave loop 11 is folded and loaded into the sheath 32 as a whole. A third developer 321 is provided at the proximal port of the sheath 32 for indicating the position of the sheath 32 relative to the film-covered stent 100 during the retraction process of the sheath 32 when the film-covered stent 100 is released.

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

[0097] First, the sheath core assembly 31 is penetrated into the main body stent 10 from the distal end and exits from the port of the branch stent 20 on the side away from the main body stent 10, and the second bare wave loop 21 of the branch stent 20 is hooked to the distal end of the sheath core assembly 31, so that a releasable hooking connection is formed between the sheath core assembly 31 and the second bare wave loop 21; since the branch stent 20 and the main body stent 10 are arranged at a certain angle in the natural expansion state, the angle range can be 60° to 90°. When the sheath core assembly 31 exits from the side of the branch stent 20 away from the main body stent 10, the branch stent 20 bends toward the proximal end of the main body stent 10 and adheres to the proximal end of the main body stent 10, as Figure 16 shown;

[0098] Then, the distal part of the main body stent 10 is gradually loaded into the sheath 32. When the proximal end of the main body stent 10 is loaded, the distal end of the axially positionable part of the sheath 32 is constricted. Then, with the first connection point P as the fulcrum, the foldable part 111 of the first bare wave ring 11 is folded towards the distal end of the main body stent 10 and approaches the first wave rod 1131a. The foldable part 111 is folded axially by 180°. At the same time, with the help of an external force, the third waveform unit 1131 of the support part 113 is opened, so that the included angle between the first wave rod 1131a and the second wave rod 1131b becomes larger (tending to 180°). With radial compression, the axial positioning part 112 approaches the second wave rod 1131b, so that the axial positioning part 112 is radially compressed within the sheath 32, as Figures 17-18 shown;

[0099] Finally, the partially folded and overall compressed first bare wave ring 11 is constricted within the sheath 32. The sheath 32 is further advanced, and the branch stent 20 is constricted within the sheath 32 until the distal end of the sheath 32 is constricted to the proximal end of the guide head 311, and the loading is completed to form a stent system, as Figures 19-20 shown. As Figure 20 shown, in this stent system, the free end 111a of the foldable part 111 that is not connected to the membrane does not interfere with the proximal end of the axial positioning part 112 (that is, they approach each other but do not contact), or the free end of the foldable part presses against the outside of the axial positioning part, so that when the first bare wave ring is released from the sheath, the foldable part 111 and the axial positioning part 111 are released in sequence, thus avoiding the axial positioning part 112 in the stent system pressing on the outside of the folded foldable part, resulting in the instantaneous release of the first bare wave ring, causing the foldable part to adhere to the large curvature side of the blood vessel while the first bare wave ring is completely released and adheres to the wall as a whole, resulting in the inability to adjust the position of the foldable part adhering to the large curvature side blood vessel wall axially.

[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-loaded stent system into the aortic arch 800 of the human body is as follows:

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

[0102] Then, as Figures 23-24 shown, the position of the stent system is adjusted so that the first imaging element 16 does not enter the supra-aortic branch. When the sheath 32 is retracted until the third imaging element 321 is close to the first imaging element 16, as Figure 23As shown in the figure, the sheath tube 32 is slowly withdrawn backward. Since there is a certain angle between the main body stent 10 and the branch stent 20, during the process that the third imaging element 321 is located between the first imaging element 16 and the second imaging element 17, and during the process that the third imaging element 321 moves away from the first imaging element 16 and approaches the second imaging element 17, the proximal end of the main body stent 10 gradually moves away from the branch stent 20; during this process, the sheath tube 32 is slowly released, and at the same time, the delivery device 30 is pushed forward. Due to the presence of the guide wire 90, the sheath core assembly 31 advances along the guide wire 90 toward the branch, and the exposed foldable part 111 moves away from the branch stent 20 (and the part close to the greater curvature side is the membrane part), until the covering film of the main body stent 10 exceeds the inflection point on the proximal side of the left subclavian branch artery 803, and then the sheath tube 32 can be continuously withdrawn backward to gradually release the proximal end of the main body stent 10. As Figure 25 shown in the figure, the foldable part 111 in the main body stent 10 is preferentially released, and the foldable part 111 is turned back to the proximal side of the opening of the left subclavian branch artery 803 and tends to fit the greater curvature side of the aortic arch 800; the sheath tube 32 is continuously withdrawn backward step by step, as Figures 25-26 shown in the figure, after the support part 113 and the axial positioning part 112 are also released and return to the natural state, due to the first half of this process, the foldable part 111 has been turned back 180° and tends to fit the greater curvature side of the aortic arch 800, while the support part 113 has not been completely released, and the first trough 1131c is in a deformed state (compared with the first bare wave loop 11 in the natural state, the β angle increases), so that the support part 113 has a restoring force toward the proximal end; and due to the deformation of the support part 113 when it is compressed (the first wave rod 1131a and the second wave rod 1131b move away from each other, making the α angle tend to 180°), as the sheath tube 32 is withdrawn backward, the foldable part 111 fits the greater curvature side of the aortic arch 800, and there is a restoring force for the first wave rod 1131a and the second wave rod 1131b to gradually approach each other. At the same time, it can drive the axial positioning part 112 to move toward the proximal end and be released. Therefore, while the axial positioning part 112 expands radially, it will also move toward the proximal end and thus fit the second side 102 of the aortic arch 800.

[0103] Finally, as Figure 27 shown in the figure, after the proximal end of the main body stent 10 is released, the sheath tube 32 is quickly withdrawn backward to release the entire main body stent 10 to isolate the aneurysm 810. Then, the second bare wave loop 21 is released through the post-release structure of the sheath core assembly 31, thereby completely releasing the branch stent 20, as Figure 28As shown in the figure; if the branch stent 20 includes a semi-binding structure 26, the limiting rod 33 can be retracted before the second bare coil 21 is released, so as to release the main body part of the branch stent 20 to fit against the inner wall of the left subclavian branch artery 803; if a branch needs to be reconstructed, the same guide wire 90 can be used to release a branch small stent along the guide wire 90 in the left subclavian branch artery 803 and anchor it to the branch stent 20; if no branch reconstruction is required, the delivery device 30 and the guide wire 90 are withdrawn from the human body.

[0104] It can be understood that the guide wire 90 can also be selected into the brachiocephalic trunk branch artery 801 or the left common carotid branch artery 802, and the branch structure is released in the brachiocephalic trunk branch artery 801 or the left common carotid branch artery 802.

[0105] Compared with the prior art, the covered stent 100 provided by the present invention does not need to set a main guide wire in the main cavity blood vessel of the aortic arch part. The guide wire 90 is directly selected into the branches above the arch to release the whole stent, and the anchoring part of the main stent 10 can be successfully released to realize the anchoring of the proximal end of the main stent 10; and even if a branch small stent is connected again, it can be realized by using the branch guide wire 90, which reduces the operation time and the operation risk.

[0106] Embodiment 2

[0107] Embodiment 2 proposes another covered stent, as Figures 29-32 shown. The same or reusable feature parts in the covered stent of Embodiment 2 and the covered stent of Embodiment 1 will not be described in detail here. The main difference is that in the covered stent of Embodiment 2, as Figures 29-30 shown, the foldable part 511 includes a first waveform unit 5111, the axial positioning part 512 includes a second waveform unit 5121, the support part 513 includes a first inclined rod 5130, and the first inclined rod 5130 is located between the first waveform unit 5111 and the second waveform unit 5121. Among them, the first inclined rod 5130 can be a straight rod inclined relative to the axis, or an arc rod inclined relative to the axis. In this embodiment, the first inclined rod 5130 is connected to the proximal end of the main covered membrane, and the included angle formed by the first inclined rod 5130 inclined relative to the axis is the same as the included angle formed by the plane where the proximal inclined incision of the main covered membrane is located relative to the axis, so as to facilitate the overall fixation of the first inclined rod 5130 on the inner edge of the proximal end of the main covered membrane.

[0108] In this embodiment, when the covered stent is compressed and sheathed, the first inclined rod 5130 approaches the axial positioning portion 512. At the same time, the foldable portion 511 folds toward the distal end with the first connection point as the fulcrum to approach the first inclined rod 5130, thereby compressing the first bare wave loop into the sheath tube. The arrangement of the first inclined rod 5130 facilitates adjusting the length occupied axially when the support portion expands, so as to coordinate the folding of the foldable portion and the compression state of the first bare wave loop when the first bare wave loop is radially compressed into the sheath tube.

[0109] As Figures 30-31 shown, the main body stent further includes a positioning wave loop 54. The positioning wave loop 54 includes 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 loop and the fixed wave loop. In this embodiment, the first bare wave loop is a circumferential integral wave loop, and the positioning wave loop 54 is a half wave loop. And both ends of the positioning wave loop 54 each include a second inclined rod 541 to be fixed to the first bare wave loop; wherein, the first bare wave loop being a circumferential integral wave loop can make the recovery reliability of the first bare wave loop after deformation high, as Figure 31 shown. In other embodiments, as Figure 32 shown, the positioning wave loop 54 and the axial positioning portion 512 are a circumferential integral wave loop, the foldable portion 511 and the support portion 513 form a half wave loop, and both ends of this half wave loop each include a first inclined rod 5130 to be fixed to the positioning wave loop 54; wherein, the positioning wave loop 54 and the axial positioning portion 512 being a circumferential integral wave loop makes the overall support property of the proximal end of the main body stent better and the force is evenly distributed.

[0110] In other embodiments, as Figure 32 shown, the support portion 513 may further include a third waveform unit 5131. The first inclined rod 5130 is connected to the third waveform unit 5131. The first inclined rod 5130 and the third waveform unit 5131 are both located between the first waveform unit 5111 and the second waveform unit 5121, and the third waveform unit 5131 is located between the first waveform unit 5111 and the first inclined rod 5130. The support portion 513 including the third waveform unit 5131 and the first inclined rod 5130 can make the length occupied axially when the support portion 513 expands not limited by the wave height of the third waveform unit 5131 when the covered stent is compressed into the sheath tube, which is convenient for the covered stent to be compressed into the sheath tube. When the support portion 513 is compressed, the axial distance is such that when the first bare wave loop is released, the recovery process is slow, reducing the possibility that the foldable portion 511 and the axial positioning portion 512 suddenly return to their original shapes and injure the inner wall of the blood vessel.

[0111] In other embodiments, the first bare wave loop includes 8 waveform units. For each of the 8 waveform units, the central angle corresponding to the arc length spanned by the two wave valleys of each waveform unit in the circumferential direction of the lumen of the main body stent is basically the same, as Figure 33As shown, it is the same as that in Embodiment 1 Figures 1-3 and Figures 5-7 The difference from the first bare wave loop in [is that] a support ring 5132 is provided at the wave crest of the support portion 513. The support ring 5132 can be formed by winding one more loop at the wave crest connection during the formation of the wave loop, which can increase the restoring force when the support portion 513 returns to its natural state during natural expansion.

[0112] In other embodiments, such as Figures 34-35 As shown, the support portion 513 may include four (two on each side) third waveform units 5131 in the middle, and two third waveform units 5131 are located on both sides of the connection line T. The specific number of waveform units included in the support portion is not limited here. When the support portion 513 includes more 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, for the purpose of facilitating the radial compression of the foldable portion 511 after folding together with the unfolded support portion 513, the overall circumferential arc length spanned by the support portion is set. Among them, a support ring 5132 is provided at the wave trough connection between two third waveform units 5131 on the same side. The support ring 5132 can be formed by winding one more loop at the wave trough connection during the formation of the wave loop to increase the restoring force between the two connected first waveform units 5131. In addition, support rings can also be provided at the wave crests of these two third waveform units to increase the overall restoring force of the support portion. The number of support rings provided is not limited, and only needs to be provided at the wave crests or wave troughs of the first bare wave loop.

[0113] Embodiment 3

[0114] Embodiment 3 proposes another covered stent and stent system. As Figures 36-42 shown, the same or reusable feature parts in the covered stent of Embodiment 3 and the covered stent of Embodiment 1 will not be elaborated here. The main difference is that in the covered stent of Embodiment 3, as Figure 36As shown, the distal end of the first bare corrugated ring 61 is connected to the proximal end of the main body film 13, and the plane where the distal end of the first bare corrugated ring 61 is located is perpendicular to the axial direction of the main body bracket 10; the proximal end of the main body film 13 is integrally flat-mouthed perpendicular to the axial direction, and a circumferential expansion part 132 is provided at the proximal end of the main body film 13, and the circumferential expansion part 132 is correspondingly arranged in the circumferential direction with respect to the support part 613, so that the corrugated units of the support part 613 are not restricted by the main body film 13 and can thus be expanded in the circumferential direction, that is, the main body film 13 does not restrict the expansion of the support part 613, so that when the foldable part 611 of the first bare corrugated ring 61 is folded to the support part with the first connection point as the fulcrum, it is radially compressed together with the expanded support part 613, so that the proximal end of the main body film does not restrict the support part from expanding in the circumferential direction, thereby enabling the foldable part to be folded smoothly; wherein, the circumferential expansion part 132 includes a notch recessed towards the distal end. In other embodiments, the circumferential expansion part may also be provided with folds in the V-shaped area, and the opening of the "V" shape faces the proximal end. It can be understood that in other embodiments, the distal end of the first bare corrugated ring may also be of an inclined cut type as in Embodiment 1, and the proximal end face of the main body film has the same inclination trend as the distal end face of the first bare corrugated ring, and its cooperation with the circumferential expansion part is easier to expand.

[0115] The expandable length of the circumferential expansion part 132 is greater than or equal to the expandable length of the support part at its corresponding position. Wherein, the expandable length of the circumferential expansion part refers to the maximum length that can be expanded on the plane where the proximal end face of the main body film is located with the distal end of the circumferential expansion part as the fulcrum and the two end parts at its proximal end moving away from each other; the expandable length of the support part refers to the maximum length that can be expanded on the plane where the proximal end face of the main body film is located with the peak of a corrugated unit of the support part as the fulcrum and the two troughs moving away from each other; as long as the expandable length of the circumferential expansion part 132 is set to be greater than or equal to the expandable length of the support part 613, so that the circumferential expansion part 132 does not restrict the expansion of the support part 613. In the present embodiment, as Figures 36-37 shown, the circumferential expansion part 132 is provided as a V-shaped notch recessed towards the distal end of the main body bracket. The V-shaped notch includes a first end point 1321 and a second end point 1322 at the proximal end, and a third end point 1323 at the distal end. The expandable length of its circumferential expansion part 132 is the sum of the connection line length between the first end point 1321 and the third end point 1323 plus the connection line length between the second end point 1322 and the third end point 1323; the support part 613 includes a corrugated unit, and the expandable length of the support part is the sum of the rod lengths of the two wave rods (the sum of the rod lengths of the first wave rod 6131a and the second wave rod 6131b as shown in the figure). In other embodiments, as Figures 38-39As shown, the circumferential expansion part 132 is set as a U-shaped notch that is recessed towards the distal end of the main body bracket. The U-shaped notch 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. Among them, 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 is perpendicular to the axial direction (or when the film is an inclined 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 deployable length of the circumferential expansion part 132 is the sum of the length of the line connecting the first end point 1321 and the third end point 1323, plus the length of the line connecting the third end point 1323 and the fourth end point 1324, plus the length of the line connecting 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, and there is no limitation here; the circumferential expansion part 132 further includes an axial buffer part 1325 to reduce the axial pulling force on the main body film 13 when the circumferential expansion part 132 is deployed. Taking the V-shaped notch as an example, when the circumferential expansion part 132 is deployed, the two wave rods (6131a, 6131b) of a waveform unit of the support part 613 move away from each other, making the support part tend to flatten, and the third end point 1323 gradually approaches the flattened support part axially, causing the third end point 1323 to gradually move away from the distal end of the main body film 13, thereby pulling the main body film in the axial direction where the third end point 1323 is located; therefore, the higher the height of the circumferential expansion part 132 in the axial direction, the greater the axial pulling force on the corresponding part of the main body film 13 when the circumferential expansion part 132 is deployed. Setting the axial buffer part 1325 to extend circumferentially can reduce the pulling force on the main body film when the circumferential expansion part is deployed, thereby reducing the deformation of the main body film 13; in the embodiment of the U-shaped notch, the connecting part of the third end point 1323 and the fourth end point 1324 is the axial buffer part 1325. Compared with the embodiment of the V-shaped notch, the deformation amount of the corresponding part of the main body film of the circumferential expansion part 132 in the axial direction is smaller to reduce the influence of the deployment of the circumferential expansion part 132 on the deformation of the main body 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 As shown, the flat bottom is as shown in Figures 38-39 ). In the embodiment of the U-shaped notch, the support part 613 includes a waveform unit, and the deployable length of the support part is the sum of the rod lengths of the two wave rods (the sum of the rod lengths of the first wave rod 6131a and the second wave rod 6131b as shown in the figure).

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

[0117] The proximal end of the first bare wave loop 61 is arranged in an inclined mouth type structure. As Figure 36 shown, in this embodiment, the proximal end of the first side of the first bare wave loop 61 axially extends beyond the proximal end of its second side, so that the proximal end of the first side of the first bare wave loop 61 is farther from the distal end of the main body bracket 10 than the proximal end of the second side; alternatively, the proximal end of the second side of the first bare wave loop axially extends beyond the proximal end of its first side, which is not limited herein. Compared with the structure where the proximal end of the first bare wave loop is a flat mouth type, it is easier to fold.

[0118] In other embodiments, as Figures 40-42 shown, the distal end face of the first bare wave loop 61 and the proximal end face of the main body film can also be arranged as the inclined cut in Embodiment 1. Combining with the setting of the circumferential unfolding part, it is beneficial for the foldable part 611 of the first bare wave loop 61 to be radially compressed with the support part 613 in the sheath tube after folding. The connection line between the third end point 1323 and the fourth end point 1324 is not perpendicular to the axial direction. Specifically, the connection line between the third end point 1323 and the fourth end point 1324 can be arranged parallel to the connection line between the first end point 1321 and the second end point 1322. That is, the axial buffer part is arranged parallel to the distal end face of the first bare wave loop. When the axial buffer part is the inclined bottom of a U-shaped notch-like structure, the inclined bottom is parallel to the distal end face of the first bare wave loop.

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

[0120] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0121] The above-described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent should be subject to the appended claims.

Claims

1. A covered stent, characterized in that, The covered stent includes a main stent and a branch stent. The main stent includes a first side and a second side. The branch stent is located on the first side. The main stent includes a first bare wave ring, a main body wave ring, and a main body covering film. The main body covering film is disposed on the main body wave ring. The first bare wave ring is connected to the proximal end of the main body covering film. The first bare wave ring 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, the axial positioning portion is close to the second side, and the support portion is connected between the foldable portion and the axial positioning portion; a circumferential unfolding portion is provided at the proximal end of the main body covering film. The circumferential unfolding portion corresponds to the support portion in the circumferential direction, so that the main body covering film does not limit the unfolding of the support portion.

2. The covered stent according to claim 1, wherein, The circumferential unfolding portion includes a notch recessed toward the distal end.

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

4. The covered stent according to claim 1, wherein, The unfoldable length of the circumferential unfolding portion is greater than or equal to the unfoldable length of the support portion at its corresponding position.

5. The covered stent according to claim 1, wherein The circumferential unfolding portion includes an axial buffer portion to reduce the axial pulling of the main body covering film when the circumferential unfolding portion unfolds.

6. The covered stent according to claim 5, characterized in that, The circumferential unfolding portion includes a U-shaped notch recessed toward the distal end. The axial buffer portion is the inclined bottom or flat bottom of the U-shaped notch.

7. The covered stent according to claim 1, characterized in that, The proximal end of the main body covering film is in an inclined cut shape; the distal end portion of the second side of the first bare wave ring axially extends beyond the distal end portion of the first side thereof, so that the distal end face of the first bare wave ring is in an inclined cut shape.

8. The covered stent according to claim 7, characterized in that, The circumferential unfolding portion includes a U-shaped notch recessed toward the distal end. The axial buffer portion is the inclined bottom of the U-shaped notch. The inclined bottom is parallel to the distal end face of the first bare wave ring.

9. The covered stent according to claim 1, characterized in that, The foldable portion includes a first waveform unit; the axial positioning portion includes a second waveform unit; the support portion includes a third waveform unit; the third waveform unit is respectively connected to the first waveform unit and the second waveform unit. 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 bracket system, characterized in that, The stent system includes a delivery device and the covered stent according to any one of claims 1-9. The delivery device includes a sheath core assembly and a sheath tube. The sheath core assembly penetrates into the distal end of the main stent and exits from the branch stent. The first bare wave ring is partially folded and loaded into the sheath tube as a whole.

11. The stent system according to claim 11, characterized in that, The delivery device further includes a guide head. Define the axial distance from the proximal side connection point of the branch stent to the proximal end of the main body covering film as L5, and define the overall axial length of the branch stent as L6. Wherein, L6 > L5. In the stent system, the branch stent is closer to the guide head axially than the proximal end of the main stent.

12. The stent system according to claim 11, characterized in that, The free end of the foldable portion and the proximal end portion of the axial positioning portion do not interfere with each other, or the free end of the foldable portion presses on the outside of the axial positioning portion.

Images