Lumen stent

Abstract

The present application relates to a kind of luminal stents, comprising first tube, the first tube includes first segment and the second segment connected with the first segment, the radial support strength of the first segment is greater than the radial support strength of the second segment, and the radial support strength of the first segment is 0.25N / cm-5N / cm when the radial length of the first segment is compressed by 50%.The above-mentioned luminal stent can make the first segment have greater radial support strength, avoid the first segment in the area released in parallel with main stent not being extruded and deformed by main stent, effectively ensure the unobstructed blood flow of branch vessel.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of interventional medical devices, and in particular to a lumen stent. BACKGROUND

[0002] In the field of aortic endoleak treatment, when the tear of a dissection is too close to a branch vessel, it is easy to cause insufficient anchoring force of an aortic stent-graft, and generally needs to use chimney technology or in-situ fenestration technology to achieve the purpose of isolating the lesion site and opening the branch vessel. Please refer to Figure 1 , wherein the chimney technology is to place an aortic stent-graft 11 in the aortic lumen, and the aortic stent-graft 11 covers the opening of a branch vessel 12, and at the same time, a branch stent 13 is released in the aortic lumen near the proximal end of the aortic stent-graft 11, so that the proximal end of the branch stent 13 enters the aortic lumen, and the distal end of the branch stent 13 enters the branch vessel 12, thereby ensuring the blood supply of the branch vessel 12. It should be noted that after the stent is implanted in the blood vessel, the blood flows from the proximal end of the stent to the distal end of the stent.

[0003] However, the branch stent used in the existing chimney technology generally uses a single material specification, and through a unified processing process, the various parts of the branch stent have the same or similar physical properties. Although such a stent has good consistency, due to the relatively large radial support strength of the aortic stent-graft, when the branch stent is in the aortic lumen together with the aortic stent-graft, the aortic stent-graft will generate a relatively large extrusion force on the proximal end of the branch stent. After the proximal end of the branch stent is pressed, the shape of the proximal end of the branch stent is poor, and is prone to deformation, and even can cause the opening of the proximal end of the branch stent to be completely closed. Moreover, when the chimney technology is performed in the aortic arch, the position, size and shape of the blood vessels in the arch will periodically change according to the pulsation of the blood, and the proximal end of the branch stent will also move with the aorta due to the abutment with the aorta. The movement of the proximal end of the branch stent will cause stimulation to the wall of the branch vessel, and even can cause damage to the wall of the branch vessel. In addition, in the aortic arch, the central axis of the opening of the branch vessel close to the aorta usually forms an angle of 90° or close to 90° with the central axis of the aorta, and when the chimney technology is performed, the branch stent needs to be able to conform to the bending of the blood vessel. However, the current branch stent is prone to folding or narrowing at the interface between the aortic lumen and the branch vessel, which affects the patency of the branch vessel. SUMMARY

[0004] Therefore, it is necessary to provide a lumen stent to solve at least one of the above technical problems.

[0005] A tubular stent, comprising a first tubular body, the first tubular body comprising a first segment and a second segment connected to the first segment, the first segment having a greater radial support strength than the second segment, the first segment being configured to be placed in an aortic lumen, and the second segment being configured to be anchored in a branch vessel; and a second tubular body disposed outside the first tubular body, one end of the second tubular body being sealingly connected to an outer surface of the first segment of the first tubular body.

[0006] In one embodiment, the first segment has a foreshortening of no more than 10%.

[0007] In one embodiment, the first segment has a length of no less than 10 mm.

[0008] In one embodiment, the first segment has a radial length that is no greater than a radial length of the second segment.

[0009] In one embodiment, the first tubular body further comprises a transition segment connecting the first segment and the second segment, the transition segment having a foreshortening that is greater than a foreshortening of the first segment.

[0010] In one embodiment, the second tubular body comprises an opening, the opening facing away from one end of the first tubular body that is distal to the second segment.

[0011] In one embodiment, an end portion of the first segment distal to the second segment extends 10-15 mm beyond an end portion of the opening of the second tubular body.

[0012] In one embodiment, the first tubular body comprises a covering and a bare stent connected to the covering, the covering comprising a first covering disposed on the first segment and a second covering disposed on the second segment, and the bare stent comprising a first radial support structure disposed on the first segment and a second radial support structure disposed on the second segment, the first radial support structure being connected to the first covering, and the second radial support structure being connected to the second covering.

[0013] In one embodiment, the first radial support structure comprises a mesh structure formed by connecting a plurality of first wave-shaped rings in an axial direction, and the second radial support structure comprises a mesh structure formed by connecting a plurality of second wave-shaped rings in an axial direction, the first wave-shaped rings and the second wave-shaped rings each having an equal number of peaks and troughs.

[0014] In one of the embodiments, the first covering film comprises a first inner film and a first outer film attached to the first inner film, the first inner film and the first outer film are both long cylindrical structures, the length of the first inner film and the first outer film along the axial direction of the first radial support structure is equal to the axial length of the first segment, the second covering film comprises a second inner film and a second outer film attached to the second inner film, the second radial support structure is located between the second inner film and the second outer film, the second inner film and the second outer film are both long cylindrical structures, and the length of the second inner film and the second outer film along the axial direction of the second radial support structure is equal to the axial length of the second segment.

[0015] The above luminal stent is provided with the first segment having a radial support strength greater than that of the second segment, and the first segment is used to be placed in the aortic lumen, and the second segment is used to be anchored in the branch vessel, so that the proximal end of the luminal stent can be prevented from being deformed by being pressed by the main stent, the blood flow of the branch vessel is not affected, and the pressure of the distal end of the luminal stent on the wall of the branch vessel is reduced; at the same time, the second tube is provided, when blood flows into the luminal stent from the proximal end, the second tube can block the gap formed between the luminal stent and the aortic covered stent due to cooperation, and effectively prevent the occurrence of type I endoleak. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The structure schematic diagram of the aortic covered stent and the branch stent implanted in the lumen in the prior art chimney technology is shown in FIG.

[0017] Figure 2 The structure schematic diagram of the luminal stent of the first embodiment of the present application is shown in FIG.

[0018] Figure 3 The structure schematic diagram of the luminal stent of the first embodiment of the present application is shown in FIG. Figure 2 The structure schematic diagram of the luminal stent and the aortic covered stent implanted in the lumen is shown in FIG.

[0019] Figure 4 The structure schematic diagram of the luminal stent and the aortic covered stent implanted in the lumen is shown in FIG. Figure 2 The structure schematic diagram of the bare stent of the luminal stent is shown in FIG.

[0020] Figure 5 The structure schematic diagram of the bare stent of the luminal stent is shown in FIG. Figure 4 The structure schematic diagram of the first radial support structure of the first segment is shown in FIG.

[0021] Figure 6 The structure schematic diagram of the first radial support structure of the first segment is shown in FIG. Figure 2 The local structure schematic diagram of the first covering film of the first segment cooperating with the first radial support structure is shown in FIG.

[0022] Figure 7 The local structure schematic diagram of the first covering film of the first segment cooperating with the first radial support structure is shown in FIG. Figure 2 The local structure schematic diagram of the second covering film of the second segment cooperating with the second radial support structure is shown in FIG.

[0023] Figure 8 for Figure 2 partial structure diagram of the third covering film and the third radial support structure of the transition section in the first embodiment of the present application;

[0024] Figure 9 for Figure 8 structure diagram of the transition section after bending in the first embodiment of the present application;

[0025] Figure 10 structure diagram of the tubular stent in the second embodiment of the present application;

[0026] Figure 11 for Figure 10 structure diagram of the bare stent in the tubular stent in the second embodiment of the present application;

[0027] Figure 12 for Figure 11 structure diagram of the first or third wave-shaped ring in the second embodiment of the present application;

[0028] Figure 13 for Figure 11 structure diagram of the second wave-shaped ring in the second embodiment of the present application;

[0029] Figure 14 for Figure 10 partial structure diagram of the third covering film and the third radial support structure of the transition section in the second embodiment of the present application;

[0030] Figure 15 partial structure diagram of the third covering film and the third radial support structure of the transition section in another embodiment of the present application;

[0031] Figure 16 structure diagram of the tubular stent in the third embodiment of the present application;

[0032] Figure 17 for Figure 16 partial structure diagram of the first radial support structure of the first subsection in the third embodiment of the present application;

[0033] Figure 18 for Figure 16 partial structure diagram of the second radial support structure of the second subsection in the third embodiment of the present application;

[0034] Figure 19 for Figure 16 partial structure diagram of the third radial support structure of the transition section in the third embodiment of the present application;

[0035] Figure 20 structure diagram of the transition section in another embodiment of the present application;

[0036] Figure 21 structure diagram of the tubular stent in the fourth embodiment of the present application;

[0037] Figure 22 for Figure 21 A schematic diagram of the structure of a bare stent in a lumen stent;

[0038] Figure 23 This is a schematic diagram of the structure of the lumen support according to the fifth embodiment of the present invention;

[0039] Figure 24 for Figure 23 A schematic diagram of the structure of the luminal stent and the main stent being implanted into the lumen. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0041] In the field of luminal stents, after a covered stent is implanted into a blood vessel, blood flow is defined to flow from the proximal end of the luminal stent to the distal end of the covered stent.

[0042] The technical solution of the present invention will be further described in detail below with reference to specific embodiments.

[0043] Example 1

[0044] Please see Figure 2 The luminal stent 10 of one embodiment of the present invention can be used as a branch stent of the chimney technique, for example, placed in the arterial lumen together with an aortic endovascular stent graft. The luminal stent 10 includes a first tube body 101, the first tube body 101 including a first segment 100, a second segment 200 and a transition segment 300 located between the first segment 100 and the second segment 200, one end of the transition segment 300 being connected to the first segment 100 and the other end being connected to the second segment, the first segment 100, the second segment 200 and the transition segment 300 being hollow tubular structures.

[0045] It should be noted that in one embodiment, the transition segment 300 may also be omitted. In this case, the first segment 100 and the second segment 200 are directly connected.

[0046] Please see Figure 3In the released state, the first segment 100 is arranged in the aorta lumen together with the aortic covered stent 20, the second segment 200 is arranged in the branch vessel 30, and the transition segment 300 connects the first segment 100 and the second segment 200. The bending deformation of the transition segment 300 enables the tubular stent 10 to complete the transition from the aorta to the branch vessel. Preferably, the end of the first segment 100 is not closer to the branch vessel than the end of the aortic covered stent 20. More preferably, the end of the first segment 100 is farther from the branch vessel than the end of the aortic covered stent 20, i.e., the first segment 100 extends beyond the end of the aortic covered stent 20 to avoid the opening of the first segment 100 being blocked by the aortic covered stent 20, which prevents the blood flow from entering the branch vessel through the first segment 100. Specifically, the length of the first segment 100 is not less than 10 mm. In the embodiment, the length of the first segment 100 is not less than 15 mm. The length of the second segment 200 is not greater than 40 mm. If the length of the second segment 200 is greater than 40 mm, the flexibility of the tubular stent 10 is poor. In the natural state, the axial length of the transition segment 300 is not greater than 3 / 4 of the total length of the first tubular body 101. If the length of the transition segment 300 exceeds 3 / 4 of the total length of the tubular stent 10, the shortening rate of the tubular stent 10 is large, which easily causes the displacement of the tubular stent 10 when released.

[0047] Further, the radial support strength of the first segment 100 is greater than that of the second segment 200. Specifically, when the radial length of the first segment 100 is compressed by 50%, the radial support strength of the first segment 100 is 0.25 N / cm to 5 N / cm, which prevents the tubular stent 10 from being compressed and deformed in the region parallel to the aortic covered stent, and effectively ensures the supply of blood flow into the branch vessel. Preferably, when the radial length of the first segment 100 is compressed by 50%, the radial support strength of the first segment 100 is 0.4 N / cm to 5 N / cm. In the embodiment, when the radial length of the first segment 100 is compressed by 50%, the radial support strength of the first segment 100 is 1 N / cm to 3 N / cm. When the radial length of the second segment 200 is compressed by 50%, the radial support strength of the second segment 200 is 0.1 N / cm to 1 N / cm.

[0048] The radial support force can be tested by a flat plate extrusion method in the present application, and the radial support strength is calculated based on the radial support force. Specifically, two parallel flat plates are used to clamp the first segment 100 in the tangential direction along the circumference of the first radial support structure, one of which is fixed on the base and the other is placed above the first segment 100, and the two flat plates are kept parallel during the test. A radial force is applied to the movable flat plate to test the size of the radial force when the first radial support structure is compressed to 50% of the original radial length. The radial support strength is equal to the radial force divided by the length of the first segment 100.

[0049] Of course, the above-mentioned flat plate extrusion method is only an example test method, and is not a limitation of the present application. Those skilled in the art can use any suitable method to test equivalently to the flat plate extrusion method.

[0050] More specifically, the shortening rate of the first segment 100 is not more than 10%, so as to avoid the first segment 100 from retracting under the impact of blood flow, so that the opening of the first segment 100 is blocked by the aortic covered stent, thereby preventing blood flow from the opening of the first segment 100 and the branch blood vessels. It should be noted that the shortening rate in the present application refers to, for example, the first segment, if the length L of the first segment in the natural state, when the two ends of the first segment are extruded by a force in the axial direction from the end to the middle, the two ends of the first segment are drawn together along the axial direction of the first segment to the middle of the first segment or one end of the first segment to the other end, until the length L' of the first segment in the axial direction does not change, and the difference between L and L' accounts for the ratio of L.

[0051] Further, the shortening rate of the first segment 100 and the second segment 200 is less than that of the transition segment 300, so that the lumen stent 10 can meet the requirement of flexibility while reducing the risk of displacement during release. Specifically, the shortening rate of the transition segment 300 is not less than 30%, so as to effectively weaken or absorb the vibration of the proximal end of the lumen stent 10 caused by the fluctuation of the aortic covered stent, and effectively avoid the displacement of the proximal end of the lumen stent 10 due to vibration, thereby ensuring the relative static of the second segment 200 and the branch blood vessels, and reducing the stimulation of the second segment 200 to the wall of the branch blood vessels. Preferably, the shortening rate of the transition segment 300 is not more than 50% to reduce the risk of displacement of the lumen stent 10 during release.

[0052] Further, the bending radius of the transition section 300 is not greater than 10 mm, so that the transition section 300 can adapt to various different shapes of blood vessels, better fit on the blood vessel wall, avoid the transition section 300 from being folded or narrowed due to the shape of the blood vessel, and ensure the patency of the blood flow of the branch blood vessel. It should be noted that the bending diameter of the transition section in the present application refers to the minimum radius that the transition section can reach under the premise of ensuring the radial shape of the transition section, that is, the length change of each part of the transition section is less than 5%. In the present embodiment, the bending radius of the transition section 300 is not greater than 5 mm. It should be noted that the overall transition section 300 can meet the shortening rate and bending radius requirements at the same time. The structure of the transition section 300 can be consistent, and the structure of the transition section 300 is improved to meet the shortening rate and bending radius requirements at the same time. Alternatively, the transition section 300 is divided into two parts, one part meets the bending radius requirement, and the other part meets the shortening rate requirement. For example, the part of the transition section 300 close to the first section 100 meets the bending radius requirement, and the part close to the second section 200 meets the shortening rate requirement.

[0053] Further, the length of the first section 100 is not greater than the length of the second section 200, which can reduce the difficulty of sheathing the lumen stent 10. In the present embodiment, the lengths of the first section 100, the second section 200 and the transition section 300 are equal.

[0054] The first tube body comprises a covering film and a bare stent connected with the covering film. Please continue to refer to Figure 2 , the covering film comprises a first covering film 110 arranged on the first section 100, a second covering film 210 arranged on the second section 200, and a third covering film 310 arranged on the transition section 300. Please refer to Figure 4 , the bare stent comprises a first radial support structure 120 arranged on the first section 100, a second radial support structure 220 arranged on the second section 200, and a third radial support structure 320 arranged on the transition section 300, the first radial support structure 120 is connected with the first covering film 110, the second radial support structure 220 is connected with the second covering film 210, and the third radial support structure 320 is connected with the third covering film 310.

[0055] Please continue to refer to Figure 4The first radial support structure 120 is formed by double-layer weaving. Specifically, the first radial support structure 120 includes a mesh structure formed by a plurality of first wave-shaped loops 121 connected in the axial direction. Each first wave-shaped loop 121 includes 5-20 wave crests and wave troughs (i.e., the first wave-shaped loop 121 includes 5-20 wave crests and 5-20 wave troughs, and the number of wave crests and wave troughs is the same), and the wave height of the first wave-shaped loop (the wave height refers to the vertical height between two adjacent wave crests and wave troughs of the first wave-shaped loop) is 2-5 mm. The plurality of first wave-shaped loops 121 are arranged in several rows in the axial direction. Each row includes two first wave-shaped loops 121 arranged side by side, and in the two first wave-shaped loops 121, the wave crests of one first wave-shaped loop 121 correspond one by one to the wave troughs of the other first wave-shaped loop 121, and the plurality of stems of one first wave-shaped loop 121 respectively overlap the plurality of stems of the other first wave-shaped loop 121, so that the two first wave-shaped loops 121 form a plurality of quadrilaterals. The wave crests and wave troughs of the first wave-shaped loops 121 of adjacent two rows are arranged opposite to each other and are hung and buckled to form an interlocking structure, so that the first wave-shaped loops 121 of the adjacent two rows can approach each other, but cannot move away from each other, which effectively controls the elongation of the first segment 100, i.e., the ability of the first segment 100 to elongate in the axial direction when subjected to an external force can be reduced, thereby reducing the risk of inaccurate positioning of the first segment 100 when released. Please refer to Figure 5 The interlocking structure of the present application refers to the metal wires forming the wave crest 1211 part of the first wave-shaped loop 121 in the right row of the adjacent two rows first pass over the metal wires forming the wave trough 1212 part of the first wave-shaped loop 121 in the left row of the adjacent two rows, so that the metal wires of the wave crests and wave troughs of the two adjacent first wave-shaped loops 121 in the two rows are hook-wound and connected into one body, thereby forming an interlocking structure.

[0056] It should be noted that in other embodiments, the first radial support structure 120 can also be formed by weaving three or more layers, i.e., each row includes three or more first wave-shaped loops 121 arranged side by side.

[0057] The second radial support structure 220 is formed by a single layer of weaving. The mesh structure of the second radial support structure 220 has a larger pore size than the mesh structure of the first radial support structure 120. Specifically, the second radial support structure 220 comprises a mesh structure formed by a plurality of second wave-shaped annular structures 221 connected in the axial direction. Specifically, the peaks and valleys of two adjacent second wave-shaped annular structures 221 are arranged opposite to each other and are buckled to form an interlocking structure. In the present embodiment, the first wave-shaped annular structure 121 and the second wave-shaped annular structure 221 have the same shape, i.e., the number of peaks and valleys, the wave height, and the included angle between the wave-shaped annular structure and the shaft of the second wave-shaped annular structure 221 are the same as those of the first wave-shaped annular structure 121. Under this condition, since the weaving density of the second radial support structure 220 is smaller than that of the first radial support structure 120, the pore size of the mesh structure of the second radial support structure 220 is larger than that of the mesh structure of the first radial support structure 120, so that the radial support strength of the second radial support structure 220 is smaller than that of the first radial support structure 120. In this way, not only can the proximal end of the luminal stent 10 be prevented from being deformed by the aortic covered stent, but also the pressure on the branch vessel wall caused by the distal end of the luminal stent 10 can be reduced.

[0058] The third radial support structure 320 comprises a plurality of third wave-shaped annular structures 321 arranged in the axial direction of the first tube body 101 in sequence, and two adjacent third wave-shaped annular structures 321 are independent of each other and do not contact each other. Preferably, the distance between two adjacent third wave-shaped annular structures 321 (i.e., the distance between the valley of one third wave-shaped annular structure 321 and the peak of the other third wave-shaped annular structure 321 in the axial direction of the transition section 300) is equal. More preferably, the distance between two adjacent third wave-shaped annular structures 321 is smaller than the wave height of the third wave-shaped annular structure 321. In the present embodiment, the distance between two adjacent third wave-shaped annular structures 321 is 1-4 mm, and the wave height of the third wave-shaped annular structure 321 is 2-5 mm. The third wave-shaped annular structure 321 has the same shape as the first wave-shaped annular structure 121 or the second wave-shaped annular structure 221. It can be understood that the distance and the wave height of the third wave-shaped annular structure can also be adjusted according to the shortening rate required by the transition section 300.

[0059] Please refer to Figure 6The first cover film 110 includes a first inner film 111 and a plurality of first outer films 112 attached to the first inner film 111, and the first radial support structure 120 is located between the first inner film 111 and the plurality of first outer films 112. Specifically, the first inner film 111 is a long cylindrical structure, and the first outer film 112 is a short cylindrical structure, i.e., the length of the first inner film 111 along the axial direction of the first radial support structure 120 is greater than the length of the first outer film 112 along the axial direction of the first radial support structure 120, and the first inner film 111 covers the inner wall of the radial support structure 121 of the entire first segment 100 to isolate blood flow. The first wave-shaped ring 121 of the first radial support structure 120 is sandwiched between the first inner film 111 and the plurality of first outer films 112 except for the positions of the wave crests and troughs. That is, the first inner film 111 covers the inner side of the first radial support structure 120, and each first outer film 112 covers a row of intermediate regions of the first wave-shaped ring 121 except for the positions of the wave crests and troughs. That is, the wave crests and troughs of each first wave-shaped ring 121 are exposed, and the other positions are covered by the first inner film 111 and the first outer film 112. Since the wave crests and troughs of each wave-shaped ring 121 are exposed, the wave crests of each first wave-shaped ring 121 can be separated from the first inner film 111 and the first outer film 112 (that is, the wave crests of each first wave-shaped ring 121 can be raised relative to the first inner film 111 and the first outer film 112), so that the characteristic of the adjacent two first wave-shaped rings 121 of the first radial support structure 120 can be exhibited, and the flexibility of the first segment 100 can be enhanced.

[0060] Please refer to Figure 7 The second cover film 210 includes a second inner film 211 and a second outer film 212 attached to the second inner film 211, and the second radial support structure 220 is located between the second inner film 211 and the second outer film 212. The second inner film 211 and the second outer film 212 are both long cylindrical structures, and the lengths of the second inner film 211 and the second outer film along the axial direction of the second radial support structure 221 are equal to the axial length of the second segment 200, so that all the second wave-shaped rings 221 of the second radial support structure 220 are sandwiched between the second inner film 211 and the second outer film 212.

[0061] Please refer to Figure 8The third film 310 comprises a third inner film 311 and a plurality of third outer films 312 adhered to the third inner film 311, and the third radial support structure 320 is located between the third inner film 311 and the plurality of third outer films 312. The two ends of the third inner film 311 are connected to the first inner film 111 and the second inner film 211, respectively. The third inner film 311 is a long cylindrical structure, and the third outer film 312 is a short cylindrical structure, that is, the length of the third inner film 311 in the axial direction of the third radial support structure 320 is greater than the length of the third outer film in the axial direction of the third radial support structure 320. Each third wave ring 321 is clamped between one third inner film 311 and one third outer film 312, and the peaks of each third wave ring 321 are exposed outside, and the valleys of each third wave ring 321 are covered by the corresponding third outer film 312 and the third inner film 311. Specifically, the third inner film 311 covers the inner side of the third radial support structure 320, and one end of each third outer film 312 is located on the outer side of the corresponding third wave ring 321, and the other end extends to the inner side of the adjacent third wave ring 321. For example, a portion of each third outer film 312 covers 1 / 2 of the area on the outer side of the corresponding third wave ring 321, that is, each third outer film 312 covers the middle position of the third wave ring 321 on the inner side.

[0062] Please refer to Figure 9 Because the peaks or valleys of each third wave ring 321 are exposed outside (that is, the peaks or valleys of each third wave ring are not covered by the third outer film 312), the peaks or valleys of each third wave ring 321 can be separated from the third outer film 312 and the third inner film 311 (that is, the peaks or valleys of each third wave ring 321 can be raised relative to the third outer film 312 and the third inner film 311). In this way, when the transition section 300 is bent, at the small bending side, among the two adjacent third wave rings 321, one third wave ring 321 can overlap the other third wave ring 321, so that the transition section 300 has good bending performance and can conform to the anatomical shape of the blood vessel. At the same time, the transition section 300 is easy to shorten and can better absorb the vibration and displacement transmitted from the first section 100, so as to ensure that the second section 200 and the branch blood vessel remain relatively static and reduce the stimulation of the second section 200 to the wall of the branch blood vessel. In this application, the small bending side refers to the side with a smaller bending radius when the transition section 300 is bent. In addition, because the peaks of the small bending side are exposed outside, the peaks of the small bending side are not easy to pierce the third inner film 311 during bending, thereby improving the service life of the transition section 300.

[0063] It should be noted that in the present embodiment, the first inner membrane 111, the second inner membrane 211 and the third inner membrane 311 are integrally formed. That is, the first inner membrane 111, the second inner membrane 211 and the third inner membrane 311 are completely identical in material and specification, and are sequentially connected along the axial direction of the first tube body 101 to form a cylindrical structure.

[0064] In the above-described tubular stent 10, the radial support strength of the first segment 100 is 0.25 N / cm to 5 N / cm when the radial length is compressed by 50%, so that the first segment 100 is not deformed by the aortic covered stent when being contacted with the aortic covered stent, and the sufficient supply of blood flow of the branch blood vessel is effectively ensured. Meanwhile, the first segment 100 has certain flexibility and anti-shortening capability, so that the first segment 100 can be more closely attached to the aortic wall and the aortic covered stent when being released, and the risk that the opening of the tubular stent 10 is covered by the aortic stent due to the retraction of the proximal end of the tubular stent 10 caused by the flushing of blood flow can be avoided. The radial support strength of the second segment 200 is less than that of the first segment 100, so that the distal end of the tubular stent 10 can be well anchored in the branch blood vessel, and the stimulation to the blood vessel wall can be controlled.

[0065] In addition, the transition segment 300 has better bending and shortening performance, so that the tubular stent 10 can adapt to various types of chimney techniques and anatomical forms of branch blood vessel access, especially when being used in the aortic arch, the pulsation of the aorta can be buffered by the transition segment 300, so that the vibration and deformation of the tubular stent 10 are limited to the first segment 100 and the transition segment 300, thereby the relative stability of the second segment 200 and the branch blood vessel can be ensured, and the stimulation to the wall of the branch blood vessel can be reduced.

[0066] Embodiment 2

[0067] The tubular stent 10a of the second embodiment of the present application is mainly used for the renal artery branch blood vessel. The chimney technique for the renal artery is mostly double chimney technique. In order to ensure the patency of the blood vessels of the two sides of the renal artery, and to reduce the compression of the double chimney by the abdominal aortic covered stent, unlike the first embodiment, please refer to Figure 10 In the tubular stent 10a, the tube diameter of the first segment 100a is less than that of the second segment 200a, and the transition segment 300 is tapered, that is, the transition segment 300 is connected between the first segment 100a and the second segment 200a, and the transition segment 300 is a truncated cone structure.

[0068] Please refer to Figure 11The structures of the first radial support structure 120a, the second radial support structure 220a and the third radial support structure 320a are similar to the second radial support structure 220 in Embodiment 1. That is, the first radial support structure 120a, the second radial support structure 220a and the third radial support structure 300a are all woven by the single-layer weaving method. For example, the single-layer wave coil structure is woven by a single nickel-titanium wire. The pore size of the mesh structure of the first radial support structure 120a is smaller than the pore size of the mesh structure of the second radial support structure 220a. Please refer to Figure 12 and 13 The number of peaks and troughs of the first wave ring 121a, the second wave ring 221a and the third wave ring 321a is the same, and the included angle α between the adjacent two side bars in the first wave ring 121a and the third wave ring 321a is equal and greater than the included angle β between the adjacent two side bars in the second wave ring 221a, so that the radial support strength of the first segment 100a and the transition segment 300a is greater than the radial support strength of the second segment 200a.

[0069] Please refer to Figure 10 The film covering method of the first film 110a is the same as the film covering method of the second film 210a, and is the same as the film covering method of the second film 210 of the second segment 200 in Embodiment 1, that is, the first film also includes a first inner film and a first outer film attached to the first inner film, the first inner film and the first outer film are both long cylindrical structures, the axial length of the first inner film and the first outer film is equal to the axial length of the first segment, the first wave ring 121a is wrapped between the first inner film and the second outer film, and the second wave ring 221a is wrapped between the second inner film and the second outer film.

[0070] Please refer to Figure 14 The third outer film 312a is a plurality of strips, and the third outer film 312a can cover the bar body of the third wave ring 321a along the circumferential direction of the third wave ring 321a, and expose the peaks and troughs of the third wave ring 321a. That is, each strip of the third outer film 312a covers the middle region of a row of third wave rings 321a except the peak and trough positions. That is, the peaks and troughs of each third wave ring 321a are exposed, and the other positions are covered by the third outer film 312a. Since the peaks and troughs of each wave ring 121 are exposed, the characteristics of the adjacent two first wave rings 321a in the third radial support structure 320a are exhibited, and the bending performance and shortening performance of the transition segment 300a are enhanced. Preferably, the width of each part of the third outer film 321a in the circumferential direction is equal, so that the transition segment 300a can bend in various directions to adapt to different blood vessel shapes.

[0071] Preferably, the width of the third outer film 312a along the axial direction of the transition section 300a is greater than or equal to 1 / 5 of the distance between the wave crests and wave troughs of the third wave-shaped annulus 321a along the axial direction of the transition section 300a and less than or equal to 4 / 5 of the distance between the wave crests and wave troughs of the third wave-shaped annulus 321a along the axial direction of the transition section 300a, so as to ensure that the third wave-shaped annulus 321a cannot be separated from the outer film while exposing the wave crests and wave troughs of the first wave-shaped annulus 321a. More preferably, the width of the third outer film 312a along the axial direction of the transition section 300a is equal to 1 / 2 of the distance between the wave crests and wave troughs of the third wave-shaped annulus 321a along the axial direction of the transition section 300a, so as to ensure that the transition section 300a has good bending and shortening properties while making the structure of the transition section 300a more stable.

[0072] Of course, the third outer film 312a can also cover the third wave-shaped annulus 321a along other directions of the third wave-shaped annulus 321a. Please refer to Figure 15 The angle between the extending direction of the third outer film 312a and the axial direction of the transition section 300a is not greater than 65°, so that the distance between the third wave-shaped annulus 321a can be greater, thereby improving the flexibility of the transition section 300a. Preferably, the angle between the extending direction of the third outer film 312a and the axial direction of the transition section 300a is 30-60°. More preferably, the angle between the extending direction of the third outer film 312a and the extending direction of the covered rod body is 90±20°, so as to help the third outer film 312a cover as many third wave-shaped annuluses as possible without changing the extending direction, thereby facilitating the difficulty of covering the film and improving the production efficiency.

[0073] Further, the third wave-shaped rings 321a are covered by the third outer film 312a to improve the stability of the coating of the transition section 300a. Further, each third outer film 312a covers all the third wave-shaped rings 321a, i.e. each third outer film 312a extends from the first third wave-shaped ring 321a to the last third wave-shaped ring 321a, and the third outer film 312a covers at least one rod of each third wave-shaped ring 321a. The longer area covered by each third outer film 312a can increase the bonding force between the third outer film 312a and the third inner film, reduce the probability of the third outer film 312a coming off, and reduce the number of the third outer film 312a, thereby reducing the difficulty of the coating process and improving the production efficiency. In this embodiment, the third outer film 312a is pulled from the rod of the first third wave-shaped ring 321a to the rod of the second third wave-shaped ring 321a, then to the rod of the third third wave-shaped ring 321a, and so on until the rod of the last third wave-shaped ring 321a, to complete the coating in one extension direction. Then the second extension direction is coated in the same way, so that all the rods of the third wave-shaped rings 321a are covered by the third outer film 312a.

[0074] Further, the width of each part of the third outer film 312a is equal, and the width of the third outer film 312a is 1 / 3-1 / 2 of the length of the rod of the third wave-shaped ring 321a, to meet the shortening rate of the transition section 300a of 30%-50% and the bending radius of the transition section 300a of less than 5 mm. Of course, in other embodiments, the number of rods covered by the third outer film 312a and the width of the third outer film 312a can be adjusted accordingly to meet the required shortening rate and bending radius of the transition section 300a. For example, the third outer film 312a can only cover part of the rods, and the widths of the plurality of third outer films 312a can also not be completely the same.

[0075] It can also be understood that the third inner film and the third outer film 312a can also have other forms. For example, the third outer film 312a is in the form of an integral film, covering all the third wave-shaped rings 321a on the outer surface of the third wave-shaped rings 321a, and the third inner film is in the form of a strip, covering the third wave-shaped rings 321a only on the inner surface of the third wave-shaped rings 321a, and covering only the first and last third wave-shaped rings 321a (i.e. the first third wave-shaped ring 321a near the first section and the last third wave-shaped ring 321a near the second section).

[0076] In the above lumen stent 10a, the first section 100a adopts a single-layer braiding manner, the included angle of the two adjacent sides of the first wave-shaped ring 121a is large, and the inner and outer membranes are covered in a whole manner, so that the radial support strength of the first section 100a is large, thereby ensuring that the first section 100a is not extruded and deformed when being released in parallel with the abdominal aortic covered stent. The transition section 300a has good bending performance and shortening performance due to the fact that the peaks and valleys of the third wave-shaped ring 321a are exposed, so that the lumen stent 10a has a better release form, and the influence of arterial pulsation on the second section 200a can be eliminated. The included angle of the two adjacent sides of the second wave-shaped ring 221a in the second section 200a is small, so that the second section 200a has a small radial support strength, and the inner and outer membranes of the second section 200a are covered in a whole manner, so that the second section 200a has a high anti-shortening capability, thereby effectively improving the adhesion performance and stability of the second section 200a.

[0077] In addition, since the number of peaks and valleys of the first wave-shaped ring 121a, the second wave-shaped ring 221a and the third wave-shaped ring 321a is the same, the overall consistency of the lumen stent 10a is good, which is beneficial to the uniform assembly and release of the lumen stent 10a.

[0078] Embodiment 3

[0079] Please refer to Figure 16 Different from embodiment 1, the bare stent of the lumen stent 10b of the third embodiment of the present application is cut from a nickel-titanium tube, and the covering film adopts a single-layer covering film structure and only includes an inner membrane, for example, a PET inner membrane. The bare stent is fixed on the covering film by a suture 140.

[0080] The first radial support structure 120b of the first section 100b adopts a whole cutting, and includes a mesh structure connected by a plurality of first wave-shaped rings 121b in the axial direction, so that the radial support strength of the first section 100b is large and is not easy to bend and deform. Specifically, the first wave-shaped ring 121b includes 5-20 peaks and valleys. Please refer to Figure 17 The connection between the peak of one of the two adjacent first wave-shaped rings 121b and the valley of the other first wave-shaped ring 121b is provided with a through hole 123 for suturing with the first covering film 110b.

[0081] The second radial support structure 220b of the second section 200b also adopts a whole cutting, and includes a plurality of connected second wave-shaped rings 221b.

[0082] Specifically, please refer to Figure 18The second radial support structure 220b comprises a plurality of second wave-shaped rings 221b arranged at intervals, wherein the adjacent second wave-shaped rings 221b are connected by connecting rods 223. Specifically, the number of connecting rods 223 between the adjacent two second wave-shaped rings 221b is 1-10, which effectively ensures the stability of the second section 200b, reduces the shortening rate of the second section 200b, and reduces the risk of displacement of the second section 200b during anchoring. More specifically, the second wave-shaped ring 221b comprises 5-20 wave crests and troughs.

[0083] It should be noted that the positions of some wave crests of the second wave-shaped ring 221b can also be provided with through holes 123 for suturing with the second film 210b.

[0084] The third radial support structure 320b of the transition section 300b is formed in a cut manner to have a plurality of independent third wave-shaped rings 321b. Specifically, the third wave-shaped ring 321b comprises 5-20 wave crests and troughs.

[0085] Please refer to Figure 19 The phase difference between the adjacent two third wave-shaped rings 321b is zero, that is, the line connecting the nearest two wave crests or the nearest two troughs of the adjacent third wave-shaped rings 321b is parallel to the axial direction of the transition section 300b. In the present embodiment, the spacing between the adjacent two third wave-shaped rings 321b (i.e., the distance in the axial direction between the trough of the first third wave-shaped ring 321b and the nearest crest of the other third wave-shaped ring 321b in the direction from the first section 100b to the second section 200b of the two adjacent third wave-shaped rings 321b) is equal to 1 / 2 of the wave height of the third wave-shaped ring 321b (the wave height refers to the vertical height between the wave crest and the trough of the third wave-shaped ring 321b), in other words, the shortening rate of the transition section 300b is 30%. Of course, in other embodiments, the ratio between the spacing between the adjacent two third wave-shaped rings 321b and the wave height of the third wave-shaped ring 321b can also be other values, as long as the shortening rate of the transition section 300b is not greater than 50%. More specifically, the third wave-shaped ring 321b is provided with a through hole 123 at each wave crest or trough position for suturing with the third film 310b.

[0086] In the present embodiment, the number of wave crests and troughs of the first wave-shaped ring 121b, the second wave-shaped ring 221b and the third wave-shaped ring 321b are equal, and the wave height of each wave-shaped ring and the included angle between the rod bodies are equal, which has good consistency.

[0087] The first cover film 110b, the second cover film 210b and the third cover film 310b are integrally formed PET films, and the first radial support structure 120b, the second radial support structure 220b and the third radial support structure 320b are respectively fixed to the outer side of the PET film by stitching. It can be understood that in other embodiments, the first radial support structure 120b, the second radial support structure 220b and the third radial support structure 320b can also be respectively fixed to the inner side of the PET film by stitching. It can also be understood that in other embodiments, the first cover film 110b, the second cover film 210b and the third cover film 310b can also be integrally formed PTFE films or other similar films.

[0088] In this embodiment, all the third wave-shaped rings 321b in the third radial support structure 320b are fixed to the third cover film 310b by stitching. Of course, in other embodiments, only part of the third wave-shaped rings 321b can be fixed to the third cover film 310b. For example, only the two end third wave-shaped rings 321b are fixed to the third cover film 310b by stitching, and the remaining third wave-shaped rings 321b are not fixed to the third cover film 310b. Please refer to Figure 20 The transition section 300b includes the third radial support structure 320b and the third cover film 310b covering the third radial support structure 320b. The structure of the third radial support structure 320b can refer to the third radial support structure 320a in Embodiment 2, that is, the third radial support structure 320b includes a mesh structure formed by connecting a plurality of third wave-shaped rings 321b in the axial direction, and the peaks and valleys of adjacent two third wave-shaped rings 321b are arranged opposite to each other and are hung and buckled to form an interlocking structure. The third cover film 310b is located on the outer side of the third radial support structure 320b (that is, the third cover film 310 only includes an outer film, without an inner film), and only the two third wave-shaped rings 321b at the ends of the third radial support structure 320b are fixed to the third cover film 320b by stitching 140, and the middle third wave-shaped rings 321b are not fixed to the third cover film 310b.

[0089] It can also be understood that a plurality of third wave-shaped rings 321b can be fixed to the third cover film 310b by stitching as needed, for example, a plurality of third wave-shaped rings 321b located at the end can be fixed to the third cover film 310b by stitching, and only a small part of the third wave-shaped rings 321b are not connected to the third cover film 310b.

[0090] Embodiment 4

[0091] Please refer to Figure 21Unlike the first embodiment, the fourth embodiment of the present application further comprises a second tube 400 sleeved on the first tube 101c, one end of the second tube 400 is sealingly connected with the outer surface of the first tube 101c. Specifically, the second tube 400 is located at the position of the first segment 100c, and the opening of the second tube 400 is directed away from the end of the first tube 101c far from the second segment 200c. When blood flows into the lumen stent 10c from the proximal end, the second tube 400 can block the gap between the lumen stent 10c and the aortic covered stent due to the cooperation, effectively preventing the occurrence of type I endoleak. Preferably, the length of the second tube 400 is less than the length of the first segment 100c. More preferably, the end of the first segment 100c far from the second segment 200c exceeds the end of the opening of the second tube 400. For example, the end of the first segment 100c far from the second segment 200c exceeds the end of the opening of the second tube 400 by 10-15 mm, so that the lumen stent 10c is better cooperated with the aortic covered stent, avoiding the occurrence of type I endoleak.

[0092] Please refer to Figure 22 The first radial support structure 120c, the second radial support structure 220c and the third radial support structure 300c are all woven in a single-layer woven manner. For example, a single-layer wave coil structure woven by a single nickel-titanium wire. That is, the structure of the first radial support structure 120c, the second radial support structure 220c and the third radial support structure 320c is similar to the second radial support structure 220 in the first embodiment. The number of wave crests and wave troughs of the first wave ring 121c, the second wave ring 221c and the third wave ring 321c are the same, and the wave height h1 of the first wave ring 121c and the third wave ring 321c is equal, and the wave height h1 is less than the wave height h2 of the second wave ring 221c, so that the radial support strength of the first segment 100c is greater than that of the second segment 200c.

[0093] In this embodiment, the covering manner of the first covering 110c, the second covering 210c and the third covering 310c is the same as that of the corresponding part in the second embodiment, which will not be repeated here.

[0094] In order to enable the second tube body 400 to better seal the gap between the luminal stent 10c and the aortic covered stent, the radial support strength of the second tube body 400 is less than that of the first segment. For example, under the same conditions, the support structure of the second tube body 400 uses a nickel-titanium wire with a smaller wire diameter. Specifically, the first tube body uses a nickel-titanium wire with a wire diameter of 0.0060-0.0080 inches, and the second tube body 400 uses a nickel-titanium wire with a wire diameter of 0.0045-0.0059 inches. In order to avoid displacement of the second tube body 400 in the gap between the luminal stent 10c and the aortic covered stent, the covering method of the second tube body 400 can be the same as that of the first segment 100c, i.e., using the inside-out whole covering method, which can make the second tube body 400 have higher shortening resistance and lower flexibility, thereby avoiding displacement of the second tube body 400 in the gap. Preferably, the thickness of the covering of the second tube body 400 is less than that of the first segment 100c, to facilitate the loading of the luminal stent 10c into the sheath and reduce the inner diameter of the sheath required for loading.

[0095] In the above luminal stent 10c, by providing the second tube body 400 on the outer periphery of the first tube body 101c, and the radial support strength of the second tube body 400 is less than that of the first tube body, so that the luminal stent 10c will not further compress the aortic covered stent during extrusion with the aortic covered stent, thereby avoiding an increase in the gap between the luminal stent 10c and the aortic covered stent, and also better filling the gap between the luminal stent 10c and the aortic covered stent, effectively preventing the occurrence of endoleak.

[0096] Embodiment 5

[0097] Please refer to Figure 23 The luminal stent 10d of the fifth embodiment of the present application is different from the fourth embodiment in that the second tube body 400a can be folded outward. Please refer to Figure 24 The luminal stent 10d corresponds to another release form, after the main stent 20 is windowed, the proximal end of the luminal stent 10d is anchored in the lumen of the main stent 20a through the window, and the distal end is located outside the main stent 20a and is anchored in the branch blood vessel 30a. When the second tube body 400a enters the inside of the main stent 20a, it is folded outward and adheres to the inside of the main stent 20a, avoiding blood leakage from the window position of the main stent 20a.

[0098] It should be noted that the first radial support structure, the second radial support structure, the third radial support structure, and the first film, the second film, and the third film are not limited to the structures used in the above embodiments. Other structures can also be used as long as the conditions are met. Moreover, the first radial support structure, the second radial support structure, and the third radial support structure in each embodiment of the present application are not unique. They can be combined with each other as long as the conditions are met. For example, the first radial support structure in Embodiment 1 can use the first film structure in Embodiment 1 or the first film structure in Embodiment 2.

[0099] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, but as long as the combinations of the technical features do not contradict each other, they should be considered within the scope of the present disclosure.

[0100] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, and these are within the scope of protection of the present application. Therefore, the scope of protection of the present application should be subject to the appended claims.

Claims

1. A lumen stent, used as a branch stent, comprising a first tubular body, characterized in that, The first tube includes a first segment and a second segment connected to the first segment. The radial support strength of the first segment is greater than that of the second segment. The first segment is used to be placed in the aortic lumen, and the second segment is used to be anchored in a branch vessel. The stent also includes a second tube disposed outside the first tube, one end of which is sealed to the outer surface of the first segment of the first tube. The shortening rate of the first segment is not greater than 10%. The first tube also includes a transition segment connecting the first segment and the second segment, the shortening rate of the transition segment being greater than that of the first segment.

2. The lumen stent according to claim 1, characterized in that, The length of the first segment is not less than 10mm.

3. The lumen stent according to claim 1, characterized in that, The diameter of the first segment is not greater than the diameter of the second segment.

4. The lumen stent according to any one of claims 1 to 3, characterized in that, The second tube includes an opening facing the end of the first tube away from the second segment.

5. The lumen stent according to claim 4, characterized in that, The end of the first segment that is far from the second segment extends 10-15 mm beyond the end of the opening of the second tube.

6. The lumen stent according to any one of claims 1 to 3, characterized in that, The first tube body includes a membrane and a bare support connected to the membrane. The membrane includes a first membrane disposed on the first segment and a second membrane disposed on the second segment. The bare support includes a first radial support structure disposed on the first segment and a second radial support structure disposed on the second segment. The first radial support structure is connected to the first membrane, and the second radial support structure is connected to the second membrane.

7. The lumen stent according to claim 6, characterized in that, The first radial support structure includes a mesh structure formed by connecting multiple first waveform rings in the axial direction, and the second radial support structure includes a mesh structure formed by connecting multiple second waveform rings in the axial direction. The number of peaks and troughs of the first waveform rings and the second waveform rings are equal.

8. The lumen stent according to claim 6, characterized in that, The second coating includes a second inner film and a second outer film adhered to the second inner film. The first coating includes a first inner film and a first outer film adhered to the first inner film. Both the first inner film and the first outer film are elongated cylindrical structures. The length of the first inner film and the first outer film along the axial direction of the first radial support structure is equal to the axial length of the first segment. The second radial support structure is located between the second inner film and the second outer film. Both the second inner film and the second outer film are elongated cylindrical structures, and the length of the second inner film and the second outer film along the axial direction of the second radial support structure is equal to the axial length of the second segment.

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