Lumen stent

Abstract

The invention relates to a lumen stent which comprises a first tube body, the first tube body comprises a first subsection and a second subsection connected with the first subsection, the radial supporting strength of the first subsection is larger than that of the second subsection, and when the diameter length of the first subsection is compressed by 50%, the radial supporting strength of the second subsection is larger than that of the first subsection. The radial supporting strength of the first subsection ranges from 0.25 N / cm to 5 N / cm. According to the lumen stent, the first section can have large radial supporting strength, it is avoided that the first section is extruded and deformed by the main stent in the release area parallel to the main stent, and it is effectively guaranteed that blood flow of branch blood vessels is smooth.

Description

Technical Field

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

[0002] In the field of aortic endovascular disease treatment, when the dissection rupture is too close to the branch vessels, it is easy to cause insufficient anchoring force of the aortic stent graft. Generally, chimney technology or in situ fenestration technology is required to simultaneously isolate the lesion site and open the branch vessels. Figure 1 The chimney technique involves placing an aortic stent graft 11 within the aortic lumen, extending over and covering the opening of a branch vessel 12. Simultaneously, a branch stent 13 is released within the aortic lumen near the proximal end of the stent graft 11, allowing the proximal end of the branch stent 13 to enter the aortic lumen and the distal end of the branch stent 13 to enter the branch vessel 12, thereby ensuring blood supply to the branch vessel 12. It should be noted that after the stent is implanted in a blood vessel, blood flow flows from the proximal end of the stent to the distal end.

[0003] The branch stents used in the existing chimney technology generally use a single raw material specification, and through a unified processing technology, each part of the branch stent has the same or similar physical properties. Although this type of stent has good consistency, due to the large radial support strength of the aortic covered stent, when the branch stent and the aortic covered stent are in the aortic cavity, the aortic covered stent will generate a large squeezing force on the proximal end of the branch stent. The proximal end of the branch stent has a poor shape after being compressed, and is easy to deform and may even cause the proximal opening of the branch stent to be completely closed. Moreover, when the chimney technology is performed on the aortic arch, the position, size and shape of the blood vessels in the arch will change periodically according to the pulsation of the blood. The proximal end of the branch stent will move with the pulsation of the aorta because it is attached to the wall of the aorta, and the distal end of the branch stent needs to be attached to the wall of the branch blood vessel. The movement of the branch stent will cause irritation to the wall of the branch blood vessel and may even cause damage to the wall of the branch blood vessel. In addition, in the aortic arch, the central axis of the branch blood vessel close to the opening of the aorta is usually at an angle of 90° or close to 90° with the central axis of the aorta. When performing the chimney technique, the branch stent needs to be able to conform to the curvature of the blood vessel. However, the current branch stent is prone to bending or stenosis at the interface between the aortic cavity and the branch blood vessel, affecting the patency of blood flow in the branch blood vessel. Summary of the Invention

[0004] Based on this, it is necessary to provide a luminal stent to solve at least one of the above technical problems.

[0005] A luminal stent comprises a first tube body, wherein the first tube body comprises a first segment and a second segment connected to the first segment, wherein the radial support strength of the first segment is greater than the radial support strength of the second segment, the first segment is used to be placed in the aortic cavity, and the second segment is used to be anchored in a branch blood vessel; the luminal stent also comprises a second tube body arranged outside the first tube body, and one end of the second tube body is sealed and connected to the outer surface of the first segment of the first tube body.

[0006] In one embodiment, the shortening rate of the first segment is no more than 10%.

[0007] In one embodiment, the length of the first segment is not less than 10 mm.

[0008] In one embodiment, the diameter length of the first segment is not greater than the diameter length of the second segment.

[0009] In one embodiment, the first tube body further includes a transition section connecting the first segment and the second segment, and the shortening rate of the transition section is greater than the shortening rate of the first segment.

[0010] In one embodiment, the second tube includes an opening, and the opening faces an end of the first tube away from the second segment.

[0011] In one embodiment, the end of the first segment away from the second segment extends beyond the end of the opening of the second tube by 10 to 15 mm.

[0012] In one embodiment, the first tube body includes a coating and a bare stent connected to the coating, the coating includes a first coating provided on the first segment and a second coating provided on the second segment, the bare stent includes a first radial support structure provided on the first segment and a second radial support structure provided on the second segment, the first radial support structure is connected to the first coating, and the second radial support structure is connected to the second coating.

[0013] In one embodiment, the first radial support structure includes a mesh structure formed by connecting a plurality of first wavy rings in the axial direction, and the second radial support structure includes a mesh structure formed by connecting a plurality of second wavy rings in the axial direction, and the number of crests and troughs of the first wavy rings and the second wavy rings are equal.

[0014] In one embodiment, the first coating includes a first inner coating and a first outer coating adhered to the first inner coating, the first inner coating and the first outer coating are both long cylindrical structures, the length of the first inner coating and the first outer coating along the axial direction of the first radial support structure is equal to the axial length of the first segment, the second coating includes a second inner coating and a second outer coating adhered to the second inner coating, the second radial support structure is located between the second inner coating and the second outer coating, the second inner coating and the second outer coating are both long cylindrical structures, and the length of the second inner coating and the second outer coating along the axial direction of the second radial support structure is equal to the axial length of the second segment.

[0015] The aforementioned luminal stent has a first segment with greater radial support strength than the second segment. The first segment is positioned within the aortic lumen, while the second segment is anchored within the branch vessel. This prevents the proximal end of the luminal stent from being squeezed and deformed by the main stent, which could affect blood flow in the branch vessel, and also reduces pressure on the branch vessel wall from the distal end of the luminal stent. Furthermore, the second tubular body seals the gap between the luminal stent and the aortic stent graft when blood flows from the proximal end, effectively preventing type I endoleak. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the structure of the chimney technology aortic stent graft and branch stent after implantation into the lumen;

[0017] Figure 2 This is a schematic structural diagram of a luminal stent according to a first embodiment of the present invention;

[0018] Figure 3 for Figure 2 The schematic diagram of the structure of the luminal stent and the aortic covered stent after implantation into the lumen;

[0019] Figure 4 for Figure 2 A schematic structural diagram of a bare stent of a luminal stent is shown;

[0020] Figure 5 for Figure 4 A schematic structural diagram of the first radial support structure of the first segment;

[0021] Figure 6 for Figure 2 A schematic diagram of the local structure of the first covering membrane of the first segment in the middle portion cooperating with the first radial support structure;

[0022] Figure 7 for Figure 2 A schematic diagram of the partial structure of the cooperation between the second covering membrane of the second segment and the second radial support structure;

[0023] Figure 8 for Figure 2 A schematic diagram of the partial structure of the cooperation between the third covering membrane and the third radial support structure of the middle transition section;

[0024] Figure 9 for Figure 8 Schematic diagram of the structure after the transition section is bent;

[0025] Figure 10 This is a schematic structural diagram of a luminal stent according to a second embodiment of the present invention;

[0026] Figure 11 for Figure 10 Schematic diagram of the structure of a bare stent in a luminal stent;

[0027] Figure 12 for Figure 11 A schematic structural diagram of the first or third wavy ring;

[0028] Figure 13 for Figure 11 Schematic diagram of the structure of the second wave-shaped ring;

[0029] Figure 14 for Figure 10 A schematic diagram of the partial structure of the cooperation between the third covering membrane and the third radial support structure of the middle transition section;

[0030] Figure 15 A schematic diagram of a partial structure of the cooperation between the third covering membrane and the third radial support structure of the transition section in another embodiment;

[0031] Figure 16 This is a schematic structural diagram of a luminal stent according to a third embodiment of the present invention;

[0032] Figure 17 for Figure 16 A schematic diagram of the partial structure of the first radial support structure of the first segment;

[0033] Figure 18 for Figure 16 A schematic diagram of the partial structure of the second radial support structure of the second segment;

[0034] Figure 19 for Figure 16 A schematic diagram of the partial structure of the third radial support structure of the middle transition section;

[0035] Figure 20 is a schematic structural diagram of a transition section in another embodiment;

[0036] Figure 21 This is a schematic structural diagram of a luminal stent according to a fourth embodiment of the present invention;

[0037] Figure 22 for Figure 21 Schematic diagram of the structure of a bare stent in a luminal stent;

[0038] Figure 23 This is a schematic structural diagram of a luminal stent according to a fifth embodiment of the present invention;

[0039] Figure 24 for Figure 23 Schematic diagram of the structure of the luminal stent and the main stent being implanted into the lumen. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present 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 only used to explain the present invention and are not intended to limit the present invention.

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

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

[0043] Example 1

[0044] See also Figure 2 A luminal stent 10 according to one embodiment of the present invention can be used as a branch stent using the chimney technique, for example, placed within the arterial lumen together with an aortic stent graft. The luminal stent 10 comprises a first tubular body 101, which includes a first segment 100, a second segment 200, and a transition segment 300 located between the first and second segments 100, 200. One end of the transition segment 300 is connected to the first segment 100, and the other end is connected to the second segment. The first segment 100, the second segment 200, and the transition segment 300 are all hollow tubular structures.

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

[0046] See also Figure 3After release, the first segment 100 is used to be placed in the aortic lumen together with the aortic stent graft 20, the second segment 200 is used to be anchored in the branch vessel 30, and the transition segment 300 connects the first segment 100 and the second segment 200. Through the bending deformation of the transition segment 300, the luminal stent 10 completes 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 stent graft 20. More preferably, the end of the first segment 100 is farther away from the branch vessel than the end of the aortic stent graft 20, that is, the first segment 100 extends beyond the end of the aortic stent graft 20 to avoid the opening of the first segment 100 being covered and blocked by the aortic stent graft, resulting in blood flow being unable to enter the branch vessel through the first segment 100. Specifically, the length of the first segment 100 is not less than 10 mm. Specifically in this embodiment, the length of the first segment 100 is not less than 15 mm. The length of the second segment 200 is no greater than 40 mm. This is because if the length of the second segment 200 is greater than 40 mm, the overall flexibility of the endoluminal stent 10 may be reduced. In its natural state, the axial length of the transition section 300 is no greater than 3 / 4 of the total length of the first tube 101. This is because if the length of the transition section 300 exceeds 3 / 4 of the total length of the endoluminal stent 10, the overall shortening rate of the endoluminal stent 10 is large, which may easily cause the endoluminal stent 10 to shift during release.

[0047] Furthermore, the radial support strength of the first segment 100 is greater than the radial support strength 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 0.25N / cm to 5N / cm, making it difficult for the luminal stent 10 to be squeezed and deformed in the area parallel to the aortic covered stent, effectively ensuring the supply of blood flow into the branch vessels. Preferably, when the radial length of the first segment 100 is compressed by 50%, the radial support strength of the first segment 100 is 0.4N / cm to 5N / cm. Specifically in this embodiment, when the radial length of the first segment 100 is compressed by 50%, the radial support strength of the first segment 100 is 1N / cm to 3N / cm. When the radial length of the second segment 200 is compressed by 50%, the radial support strength of the second segment 200 is 0.1N / cm to 1N / cm.

[0048] In this application, the flat plate extrusion method can be used to test the radial support force, and then the radial support strength can be calculated based on the radial support force. Specifically, two parallel flat plates are used to clamp the first segment 100 in a tangential direction along the circumference of the first radial support structure. One fixed plate is fixed to the base, and a movable plate is placed above the first segment 100. During the test, the two plates are always kept parallel. A radial force is applied to the movable plate to test the magnitude of the radial force when the first radial support structure is compressed from its original radial length to 50%. 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 exemplary test method and is not intended to limit the present invention. A person skilled in the art may use any suitable method to perform a test equivalent to the flat plate extrusion method.

[0050] More specifically, the shortening rate of the first segment 100 is no greater than 10% to prevent the first segment 100 from retracting under the impact of blood flow to the point where the opening of the first segment 100 is blocked by the aortic stent graft, thereby preventing blood flow from being unable to branch blood vessels through the opening of the first segment 100. It should be noted that the shortening rate in this application refers to, taking the first segment as an example, if the length L of the first segment in its natural state is L, when both ends of the first segment are simultaneously squeezed from the end toward the middle in the axial direction, so that the two ends of the first segment move toward the center of the first segment along the axial direction of the first segment, or one end of the first segment moves toward the other end until, while maintaining the angle between the two end faces of the first segment and its axial direction the same as in the natural state, the length of the first segment in its axial direction no longer changes, and the ratio of the difference between L and L' to L.

[0051] Furthermore, the shortening rates of the first segment 100 and the second segment 200 are both less than the shortening rate of the transition segment 300. This allows the luminal stent 10 to meet compliance requirements while reducing the risk of displacement during release. Specifically, the shortening rate of the transition segment 300 is no less than 30%. This effectively reduces or absorbs vibrations caused by the fluctuations of the aortic stent graft at the proximal end of the luminal stent 10 and effectively prevents displacement of the proximal end of the luminal stent 10 due to vibrations, thereby ensuring that the second segment 200 and the branch vessel remain relatively stationary and reducing irritation of the branch vessel wall by the second segment 200. Preferably, the shortening rate of the transition segment 300 is no more than 50% to reduce the risk of displacement of the luminal stent 10 during release.

[0052] Furthermore, the bend radius of the transition section 300 is no greater than 10 mm, allowing it to adapt to various blood vessel shapes and better adhere to the vessel wall. This prevents the transition section 300 from being bent or narrowed due to conforming to the vessel shape, thereby ensuring smooth blood flow in the branch vessels. It should be noted that the bend diameter of the transition section in this application refers to the minimum radius that the transition section can achieve by bending its ends toward the center while maintaining the radial shape of the transition section, i.e., when the length variation of each portion of the transition section is less than 5%. Specifically, in this embodiment, the bend radius of the transition section 300 is no greater than 5 mm. It should be noted that the entire transition section 300 can simultaneously meet the shortening ratio and bending radius requirements. This can be achieved by having a uniform structure of the transition section 300 and improving the structure of the transition section 300 to meet both the shortening ratio and bending radius requirements. Alternatively, the transition section 300 can be divided into two parts, one of which meets the bending radius requirement and the other meets the shortening ratio requirement. For example, the portion of the transition section 300 close to the first segment 100 meets the requirement of the bending radius, and the portion close to the second segment 200 meets the requirement of the shortening ratio.

[0053] Furthermore, the diameter of the first segment 100 is not greater than that of the second segment 200, which can reduce the difficulty of sheathing the endoluminal stent 10. In this embodiment, the diameters of the first segment 100, the second segment 200 and the transition segment 300 are equal.

[0054] The first tube body includes a membrane and a bare stent connected to the membrane. Figure 2 The coating includes a first coating 110 disposed on the first segment 100, a second coating 210 disposed on the second segment 200, and a third coating 310 disposed on the transition segment 300. Please refer to Figure 4 The bare stent includes a first radial support structure 120 arranged on the first segment 100, a second radial support structure 220 arranged on the second segment 200, and a third radial support structure 320 arranged on the transition segment 300. The first radial support structure 120 is connected to the first coating 110, the second radial support structure 220 is connected to the second coating 210, and the third radial support structure 320 is connected to the third coating 310.

[0055] Please continue reading Figure 4, the first radial support structure 120 is woven in a double-layer braiding manner. Specifically, the first radial support structure 120 includes a mesh structure formed by connecting a plurality of first wave-shaped rings 121 in the axial direction. Each first wave-shaped ring 121 includes 5 to 20 peaks and troughs (that is, the first wave-shaped ring 121 includes 5 to 20 peaks and 5 to 20 troughs, and the number of peaks and troughs is the same), and the wave height of the first wave-shaped ring (the wave height refers to the vertical height between two adjacent peaks and troughs of the first wave-shaped ring) is 2 to 5 mm. Multiple first wave-shaped rings 121 are arranged in several rows along the axial direction. Each row includes two first wavy rings 121 arranged side by side. In the two first wavy rings 121, the multiple peaks of one first wavy ring 121 correspond one-to-one with the multiple troughs of the other wavy ring 121, and the multiple rods of one wavy ring 121 overlap one-to-one with the multiple rods of the other wavy ring 121, so that the two first wavy rings 121 form a plurality of quadrilaterals. The peaks and troughs of the first wavy rings 121 in two adjacent rows are arranged relative to each other and interlocked with each other to form an interlocking structure. In this way, the first wavy rings 121 in two adjacent rows can approach each other but cannot move away from each other. This effectively controls the elongation of the first segment 100, that is, it can reduce the ability of the first segment 100 to stretch axially when subjected to external force, 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 wire forming the crest 1211 part of the first wave-shaped ring 121 in the right row of two adjacent rows first passing over the metal wire forming the trough 1212 part of the first wave-shaped ring 121 in the left row of two adjacent rows, so that the metal wires of the crest and trough of the two adjacent first wave-shaped rings 121 in the two rows are hooked and connected into one, thereby forming an interlocking structure.

[0056] It should be noted that, in other embodiments, the first radial support structure 120 may also be formed by weaving three or more layers, that is, each row includes three or more first wavy rings 121 arranged side by side.

[0057] The second radial support structure 220 is formed using a single-layer braiding method. The mesh structure of the second radial support structure 220 has a larger aperture than the mesh structure of the first radial support structure 220. Specifically, the second radial support structure 220 comprises a mesh structure formed by a plurality of second wavy rings 221 connected in the axial direction. Specifically, the crests and troughs of two adjacent second wavy rings 221 are arranged opposite each other and interlock with each other to form an interlocking structure. In this embodiment, the shapes of the first wavy ring 121 and the second wavy ring 221 are exactly the same, that is, the number of wave crests and wave troughs, and the angle between the wave height and the rod body of the second wavy ring 221 are the same as those of the first wavy ring 221. Under this condition, since the weaving density of the second radial support structure 220 is less than the weaving density of the first radial support structure 120, the aperture of the mesh structure of the second radial support structure 220 is greater than the aperture of the mesh structure of the first radial support structure, so that the radial support strength of the second radial support structure 220 is less than the radial support strength of the first radial support structure 120. This can not only prevent the proximal end of the luminal stent 10 from being squeezed and deformed by the aortic covered stent, but also reduce the pressure caused by the distal end of the luminal stent 10 on the branch blood vessel wall.

[0058] The third radial support structure 320 includes a plurality of third wave-shaped rings 321 arranged in sequence along the axial direction of the first tube body 101. Adjacent third wave-shaped rings 321 are independent of each other and do not contact each other. Preferably, the spacing between two adjacent third wave-shaped rings 321 (i.e., the distance along the axial direction of the transition section 300 between the trough of one third wave-shaped ring 321 and the peak of the other third wave-shaped ring 321 in two adjacent third wave-shaped rings 321) is equal. More preferably, the spacing between two adjacent third wave-shaped rings 321 is less than the wave height of the third wave-shaped ring 321. In this embodiment, the spacing between two adjacent third wave-shaped rings 321 is 1 to 4 mm, and the wave height of the third wave-shaped ring 321 is 2 to 5 mm. The third wave-shaped ring 321 has the same shape as the first wave-shaped ring 121 or the second wave-shaped ring 221. It is understandable that the spacing and wave height of the third wave-shaped ring can also be adjusted according to the shortening rate that the transition section 300 needs to achieve.

[0059] See also Figure 6The first coating 110 includes a first inner membrane 111 and multiple first outer membranes 112 attached to the first inner membrane 111. The first radial support structure 120 is located between the first inner membrane 111 and the multiple first outer membranes 112. Specifically, the first inner membrane 111 is a long cylindrical structure, and the first outer membrane 112 is a short cylindrical structure. That is, the axial length of the first inner membrane 111 along the first radial support structure 120 is greater than the axial length of the first outer membrane 112 along the first radial support structure 120. The first inner membrane 111 covers the entire inner wall of the radial support structure 121 of the first segment 100 to isolate blood flow. The first corrugated ring 121 of the first radial support structure 120 is sandwiched between the first inner membrane 111 and the multiple first outer membranes 112 except at the peaks and troughs. That is, the first inner membrane 111 entirely covers the inner side of the first radial support structure 120, and each first outer membrane 112 covers the middle region of a row of first wavy rings 121, excluding the peaks and troughs. In other words, the peaks and troughs of each first wavy ring 121 are exposed, while the rest of the region is covered by the first inner membrane 111 and the first outer membrane 112. Because the peaks and troughs of each wavy ring 121 are exposed, the peaks of each first wavy ring 121 can be separated from the first inner membrane 111 and the first outer membrane 112 (that is, the peaks of each first wavy ring 121 can be tilted relative to the first inner membrane 111 and the first outer membrane 112). This allows the close proximity of two adjacent first wavy rings 121 in the first radial support structure 120 to be utilized, thereby enhancing the flexibility of the first segment 100.

[0060] See also Figure 7 The second covering film 210 includes a second inner film 211 and a second outer film 212 adhered to the second inner film 211. 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 length of the second inner film 211 and the second outer film along the axial direction of the second radial support structure 221 is equal to the axial length of the second segment 200, so that all the second wavy rings 221 of the second radial support structure 220 are clamped between the second inner film 211 and the second outer film 212.

[0061] See also Figure 8The third coating 310 includes a third inner film 311 and a plurality of third outer films 312 bonded to the third inner film 311. The third radial support structure 320 is located between the third inner film 311 and the plurality of third outer films 312. The 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, while the third outer film 312 is a short cylindrical structure. That is, the axial length of the third inner film 311 along the third radial support structure 320 is greater than the axial length of the third outer film along the third radial support structure 320. Each third corrugated ring 321 is sandwiched between a third inner film 311 and a third outer film 312. The crest of each third corrugated ring 321 is exposed, while the trough of each third corrugated ring 321 is covered by the corresponding third outer film 312 and third inner film 311. Specifically, the third inner film 311 entirely covers the inner side of the third radial support structure 320, and one end of each third outer film 312 is located outside the corresponding third wavy ring 321, and the other end extends to the inner side of the adjacent third wavy ring 321. For example, a portion of each third outer film 312 covers the outer half of the corresponding third wavy ring 321, that is, each third outer film 312 starts covering the middle of the inner third wavy ring 321.

[0062] See also Figure 9 Since the crest or trough of each third wave-shaped ring 321 is exposed (that is, the crest or trough of each third wave-shaped ring is not covered by the third outer film 312), the crest or trough of each third wave-shaped ring 321 can be separated from the third outer film 312 and the third inner film 311 (that is, the crest or trough of each third wave-shaped ring 321 can be tilted relative to the third outer film 312 and the third inner film 311). In this way, when the transition section 300 is bent, On the lesser bend side, one of the two adjacent third wave-shaped rings 321 can overlap with the other third wave-shaped ring 321, thereby enabling the transition section 300 to have better bending performance and be able to conform to the anatomical morphology of the blood vessel. At the same time, the transition section 300 is easily shortened and can better absorb the vibration and displacement transmitted from the first segment 100, thereby ensuring that the second segment 200 and the branch vessel remain relatively still and reducing the stimulation of the second segment 200 on the branch vessel wall. In this application, the lesser bend side refers to the side with a smaller bending radius when the transition section 300 is bent. In addition, precisely because the wave crests on the lesser bend side are exposed, the wave crests on the lesser bend side are less likely to pierce the third endothelium 311 during bending, thereby increasing the service life of the transition section 300.

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

[0064] In the aforementioned endoluminal stent 10, the first segment 100 has a radial support strength of 0.25 N / cm to 5 N / cm when its diameter is compressed by 50%. This prevents the first segment 100 from being squeezed and deformed by the aortic stent graft when in contact with the stent graft, effectively ensuring sufficient blood flow to the branch vessels. Furthermore, the first segment 100 has a certain degree of flexibility and anti-shortening capability, allowing the first segment 100 to better conform to the aortic wall and the aortic stent graft when released, and is less likely to cause the proximal end of the endoluminal stent 10 to retract due to blood flow, thereby reducing the risk of the stent graft opening being covered by the aortic stent. The radial support strength of the second segment 200 is less than that of the first segment 100, ensuring that the distal end of the endoluminal stent 10 is well anchored within the branch vessel while also limiting its irritation to the vessel wall.

[0065] In addition, the transition section 300 has better bending and shortening properties, so that the luminal stent 10 can adapt to various types of chimney procedures and branch vessel access anatomical morphologies. Especially when used in the aortic arch, the pulsation of the aorta can be buffered by the transition section 300, so that the vibration deformation of the luminal stent 10 remains in the first segment 100 and the transition section 300, thereby ensuring the relative stability of the second segment 200 and the branch vessels, and reducing stimulation to the branch vessel walls.

[0066] Example 2

[0067] The second embodiment of the present invention is a luminal stent 10a, which is mainly used for renal artery branch vessels. The renal artery chimney technology mostly adopts double chimney technology. In order to ensure the patency of the renal arteries on both sides and to reduce the pressure of the double chimney on the abdominal aortic stent graft, the difference from the first embodiment is that Figure 10 In the luminal stent 10a, the diameter of the first segment 100a is smaller than the diameter of the second segment 200a, and the transition segment 300 is a tapered transition, 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] See also 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 Example 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 using a single-layer weaving method. For example, a single-layer wave coil structure woven from a single nickel-titanium wire is used. The aperture of the mesh structure of the first radial support structure 120a is smaller than the aperture of the mesh structure of the second radial support structure 220a. Please refer to Figure 12 and 13 The first, second, and third waveform rings 121a, 221a, and 321a have the same number of crests and troughs, and the angles α between the adjacent rods on both sides of the first and third waveform rings 121a, 321a are equal and greater than the angle β between the adjacent rods on both sides of the second waveform ring 221a, thereby making the radial support strength of the first segment 100a and the transition segment 300a greater than the radial support strength of the second segment 200a.

[0069] Please continue reading Figure 10 The coating method of the first coating 110a is the same as the coating method of the second coating 210a, and both are the same as the coating method of the second coating 210 of the second segment 200 in Example 1, that is, the first coating also includes a first inner membrane and a first outer membrane adhered to the first inner membrane, the first inner membrane and the first outer membrane are also long cylindrical structures, the axial length of the first inner membrane and the first outer membrane is equal to the axial length of the first segment, the first corrugated ring 121a is wrapped between the first inner membrane and the second outer membrane, and the second corrugated ring 221a is wrapped between the second inner membrane and the second outer membrane.

[0070] See also Figure 14 The third outer membrane 312a comprises multiple strips, each of which covers the rod of the third wavy ring 321a along its circumference, while exposing the crests and troughs of the third wavy ring 321a. Specifically, each strip of the third outer membrane 312a covers the middle region of a row of third wavy rings 321a, excluding the crests and troughs. In other words, the crests and troughs of each third wavy ring 321a are exposed, while all other locations are covered by the third outer membrane 312a. Since the crests and troughs of each wavy ring 121 are exposed, the proximity of two adjacent first wavy rings 321a in the third radial support structure 320a is utilized, enhancing the bending and shortening properties of the transition section 300a. Preferably, the widths of various parts of the third outer membrane 321a along the circumferential direction are equal, so that the transition section 300a can bend in various directions to adapt to different blood vessel morphologies.

[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 crest and trough of the third wave-shaped ring 321a it holds, and less than or equal to at least 4 / 5 of the distance between the crest and trough of the third wave-shaped ring 321a it holds. This ensures that the third wave-shaped ring 321a it holds cannot detach from the covering while also exposing the crests and troughs of the first wave-shaped ring 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 crest and trough of the third wave-shaped ring 321a it holds, ensuring that the transition section 300a has good bending and shortening properties while also providing a more stable structure.

[0072] Of course, the third outer film 312a can also cover the third wavy ring 321a along other directions of the third wavy ring 321a. Figure 15 The angle between the extension direction of the third outer film 312a and the axial direction of the transition section 300a is no greater than 65°, which increases the movable distance between the third corrugated rings 321a and improves the flexibility of the transition section 300a. Preferably, the angle between the extension 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 extension direction of the third outer film 312a and the extension direction of the covered rod is 90±20°. This helps the third outer film 312a cover as many third corrugated rings as possible without changing its extension direction, thereby reducing the difficulty of lamination and improving production efficiency.

[0073] Furthermore, all rods of the third wave-shaped rings 321a are covered with a third outer film 312a to improve the stability of the coating on the transition section 300a. Furthermore, each third outer film 312a covers all third wave-shaped rings 321a. That is, each third outer film 312a extends from the first third wave-shaped ring 321a to the last third wave-shaped ring 321a. 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 increases the bonding strength between each third outer film 312a and the third inner film, reducing the probability of the third outer films 312a becoming loose. Furthermore, the number of third outer films 312a can be reduced, thereby reducing the difficulty of the coating process and improving production efficiency. In this embodiment, during coating, the third outer film 312a is pulled from the rod position of the first third wavy ring 321a to the rod of the second third wavy ring 321a, and then pulled to the rod of the third third wavy ring 321a, until the rod of the last third wavy ring 321a, completing the coating in one extension direction, and then coating in the second extension direction is performed according to the same method, so that all the rods on all the third wavy rings 321a are covered with the third outer film 312a.

[0074] Furthermore, the width of each portion of the third outer film 312a is equal, and the width of the third outer film 312a is 1 / 3 to 1 / 2 of the length of the rod of the third corrugated ring 321a, ensuring that the shortening rate of the transition section 300a is between 30% and 50%, and the bending radius of the transition section 300a is less than 5 mm. Of course, in other embodiments, the amount of rod covered by the third outer film 321a and the width of the third outer film 321a 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 a portion of the rod, and the widths of multiple third outer films 312a can also be different.

[0075] It can also be understood that the third inner membrane and the third outer membrane 312a can also take other forms. For example, the third outer membrane 312a is in the form of a whole membrane, covering all the third waveform rings 321a on the outer surface of the third waveform ring 321a, and the third inner membrane is a strip structure, only the inner surface of the third waveform ring 321a covers the third waveform ring 321a, and only covers the two third waveform rings 321a at the head and tail ends (i.e., the first third waveform ring 321a near the first segment and the last waveform ring 321a near the second segment).

[0076] In the aforementioned endoluminal stent 10a, the first segment 100a utilizes a single-layer braid. The angle between adjacent rods of the first wavy ring 121a is large, and the inner and outer membranes are covered with a single layer. This provides the first segment 100a with greater radial support strength, thereby ensuring that the first segment 100a is not deformed during parallel deployment alongside the abdominal aortic stent graft. The transition segment 300a, with the crests and troughs of the third wavy ring 321a exposed, exhibits superior bending and shortening properties, ensuring an optimal deployment configuration for the endoluminal stent 10a while also minimizing the effects of arterial pulsation on the second segment 200a. The angle between the adjacent two side rods of the second wavy ring 221a in the second segment 200a is small, so that the second segment 200a has a smaller radial support strength. At the same time, the second segment 200a adopts the method of covering the inner and outer membranes as a whole, so that the second segment 200a has a higher anti-shortening ability, thereby effectively improving the wall adhesion performance and stability of the second segment 200a.

[0077] In addition, since the first wave-shaped ring 121a, the second wave-shaped ring 221a and the third wave-shaped ring 321a have the same number of crests and troughs, the overall consistency of the luminal stent 10a is better, which is conducive to the uniform assembly and release of the luminal stent 10a.

[0078] Example 3

[0079] See also Figure 16 Different from Example 1, the bare stent of the luminal stent 10b of the third embodiment of the present invention is cut from a nickel-titanium tube, and the coating adopts a single-layer coating structure, which only includes an inner membrane, for example, a PET inner membrane, and the bare stent is fixed on the coating by sutures 140.

[0080] The first radial support structure 120b of the first segment 100b is cut as a whole and comprises a mesh structure formed by connecting a plurality of first wave-shaped rings 121b in the axial direction. This provides the first segment 100b with a greater radial support strength and is less susceptible to bending and deformation. Specifically, the first wave-shaped ring 121b comprises 5 to 20 wave crests and troughs. Figure 17 In two adjacent first wave-shaped rings 121b, a through hole 123 for suturing with the first covering film 110b is provided at the connection between the wave crest of one first wave-shaped ring 121b and the wave trough of the other wave-shaped ring 121b.

[0081] The second radial support structure 220b of the second segment 200b is also cut integrally and includes a plurality of connected second wave-shaped rings 221b.

[0082] Specifically, see Figure 18The second radial support structure 220b includes a plurality of spaced-apart second wavy rings 221b, with adjacent second wavy rings 221b connected by connecting rods 223. Specifically, the number of connecting rods 223 between two adjacent second wavy rings 221b ranges from 1 to 10, effectively ensuring the stability of the second segment 200b, reducing its shortening rate, and lowering the risk of displacement during anchoring. More specifically, the second wavy rings 221b include 5 to 20 peaks and troughs.

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

[0084] The third radial support structure 320b of the transition section 300b is formed by cutting to form a plurality of independent third wave-shaped rings 321b. Specifically, the third wave-shaped rings 321b include 5 to 20 wave crests and wave troughs.

[0085] Please also refer to Figure 19 The phase difference between two adjacent third wave-shaped rings 321b is zero, that is, the line connecting the two closest crests or the two closest troughs of adjacent third wave-shaped rings 321b is parallel to the axial direction of the transition section 300b. In this embodiment, the spacing between two adjacent third wave-shaped rings 321b (that is, the axial distance between the trough of one third wave-shaped ring 321b and the crest of the other third wave-shaped ring 321b closest to the trough, as viewed from the first segment 100b to the second segment 200b) is equal to 1 / 2 of the wave height of the third wave-shaped ring 321b (wave height refers to the vertical height between the crest and 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 of the spacing between two adjacent third wave-shaped rings 321b to the wave height of the third wave-shaped rings 321b can also be other values, as long as the shortening rate of the transition section 300b is ensured to be no greater than 50%. More specifically, each wave crest or wave trough of the third wave-shaped ring 321b is provided with a through hole 123 for suturing with the third covering film 310b.

[0086] In this embodiment, the numbers of wave crests and wave troughs of the first wave ring 121b, the second wave ring 221b and the third wave ring 321b are equal, and the wave height of each wave ring and the angle between the rods are equal, which has good consistency.

[0087] The first covering film 110b, the second covering film 210b, and the third covering film 310b are formed of an integrally formed PET film, and the first radial support structure 120b, the second radial support structure 220b, and the third radial support structure 320b are each secured to the outside of the PET film by sutures. It is 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 secured to the inside of the PET film by sutures. It is also understood that in other embodiments, the first covering film 110b, the second covering film 210b, and the third covering film 310b can also be formed of an integrally formed PTFE film or other similar film.

[0088] In this embodiment, all third wave-shaped rings 321b in the third radial support structure 320b are fixed to the third covering 310b by sutures. Of course, in other embodiments, only some of the third wave-shaped rings 321b and the third covering 310b may be fixed by sutures. For example, only the third wave-shaped rings 321b at the two ends are fixed to the third covering 310b by sutures, and the remaining third wave-shaped rings 321b and the third covering 310b are not fixedly connected. Figure 20 The transition section 300b includes a third radial support structure 320b and a third coating 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 Example 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 crests and troughs of two adjacent third wave-shaped rings 321b are arranged opposite to each other and hooked together to form an interlocking structure. The third coating 310b is located on the outside of the third radial support structure 320b (that is, the third coating 310 only includes an outer membrane and no inner membrane). The third radial support structure 320b only has two third wave-shaped rings 321b at both ends fixedly connected to the third coating 320b by sutures 140, and the middle third wave-shaped ring 321b is not fixed to the third coating 310b.

[0089] It can also be understood that, as needed, multiple third wavy rings 321b can be fixed to the third coating 310b by sutures. For example, multiple third wavy rings 321b located at the end can be fixed to the third coating 310b by sutures, leaving only a small number of third wavy rings 321b unconnected to the third coating 310b.

[0090] Example 4

[0091] See also Figure 21, different from Example 1, the luminal stent 10c of the fourth embodiment of the present invention also includes a second tube body 400 that is sleeved outside the first tube body 101c, and one end of the second tube body 400 is sealed and connected to the outer surface of the first tube body 101c. Specifically, the second tube body 400 is located at the position of the first segment 100c, and the opening of the second tube body 400 is oriented toward the end of the first tube body 101c away from the second segment. When blood flows into the luminal stent 10c from the proximal end, the second tube body 400 can block the gap formed by the cooperation between the luminal stent 10c and the aortic covered stent, effectively preventing the occurrence of type I endoleak. Preferably, the length of the second tube body 400 is less than the length of the first segment 100c. More preferably, the end of the first segment 100c away from the second segment 200c exceeds the end of the opening of the second tube body 400. For example, the end of the first segment 100c away from the second segment 200c exceeds the end of the opening of the second tube body 400 by 10 to 15 mm, so that the luminal stent 10c better cooperates with the aortic covered stent to avoid the occurrence of type I endoleak.

[0092] See also Figure 22 The first radial support structure 120c, the second radial support structure 220c, and the third radial support structure 300c are all woven using a single-layer braiding method. For example, a single-layer corrugated ring structure woven from a single nickel-titanium wire is used. That is, the structures of the first radial support structure 120c, the second radial support structure 220c, and the third radial support structure 320c are similar to the second radial support structure 220 in Example 1. The first wave-shaped ring 121c, the second wave-shaped ring 221c, and the third wave-shaped ring 321c have the same number of peaks and troughs, and the wave height h1 of the first wave-shaped ring 121c and the third wave-shaped ring 321c is equal, and the wave height h1 is less than the wave height h2 of the second wave-shaped ring 221c, thereby making the radial support strength of the first segment 100c greater than the radial support strength of the second segment 200c.

[0093] In this embodiment, the laminating methods of the first coating 110 c , the second coating 210 c , and the third coating 310 c are the same as those of the corresponding parts in Embodiment 2, and are not described again herein.

[0094] To ensure that the second tube body 400 can effectively seal the gap between the endoluminal stent 10c and the aortic stent graft, for example, the radial support strength of the second tube body 400 is less than that of the first segment. For example, all other conditions being equal, the support structure of the second tube body 400 utilizes nickel-titanium wire with a smaller diameter. Specifically, the first tube body utilizes nickel-titanium wire with a diameter of 0.0060 to 0.0080 inches, while the second tube body 400 utilizes nickel-titanium wire with a diameter of 0.0045 to 0.0059 inches. To prevent the second tube body 400 from shifting within the gap between the endoluminal stent 10c and the aortic stent graft, the second tube body 400 can be coated in the same manner as the first segment 100c, using a single, internal and external coating. This provides the second tube body 400 with a higher resistance to shortening and a lower degree of compliance, thereby preventing the second tube body 400 from shifting within the gap. Preferably, the thickness of the coating of the second tube body 400 is smaller than the thickness of the coating of the first segment 100c, so as to facilitate the insertion of the luminal stent 10c into the sheath tube and reduce the inner diameter of the sheath tube required for the insertion.

[0095] In the above-mentioned luminal stent 10c, by arranging 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 the radial support strength of the first tube body, the luminal stent 10 will not further compress the arterial coated stent during the squeezing process with the arterial coated stent, thereby avoiding the increase of the gap between the luminal stent 10c and the arterial coated stent. At the same time, it can also better fill the gap between the luminal stent 10c and the arterial coated stent, effectively preventing the occurrence of internal leakage.

[0096] Example 5

[0097] See also Figure 23 The endoluminal stent 10d of the fifth embodiment of the present invention is different from that of the fourth embodiment in that the second tube 40a can be bent outward. Figure 24 The luminal stent 10d utilizes another release mechanism. After the main stent 20 is fenestrated, the proximal end of the luminal stent 10d passes through the fenestration and is anchored within the lumen of the main stent 20a. The distal end of the luminal stent 10d is located outside the main stent 20a and anchored within the branch vessel 30a. Once the second tube 400a enters the main stent 20a, it is turned outward and adheres to the inside of the main stent 20a, preventing blood from leaking through the fenestration.

[0098] It should be noted that the first radial support structure, the second radial support structure, the third radial support structure, and the first coating, the second coating, and the third coating are not limited to the structures adopted in the above embodiments. When the conditions are met, other structures may also be adopted. Moreover, the first radial support structure, the second radial support structure, the third radial support structure in each embodiment of the present invention, and the first coating, the second coating, and the third coating are not uniquely fixed. When the conditions are met, they can be combined with each other. For example, the first radial support structure in Example 1 may adopt the first coating structure in Example 1, or may adopt the first coating structure in Example 2.

[0099] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0100] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A luminal stent used as a branch stent, comprising a first tube body, characterized in that: The first tube body includes a first segment and a second segment connected to the first segment, the radial support strength of the first segment is greater than the radial support strength of the second segment, the first segment is used to be placed in the aortic cavity, and the second segment is used to anchor in the branch blood vessel; the luminal support also includes a second tube body arranged outside the first tube body, and one end of the second tube body is sealed and connected to the outer surface of the first segment of the first tube body.

2. The endoluminal stent according to claim 1, characterized in that: The shortening rate of the first segment is no more than 10%.

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

4. The endoluminal stent according to claim 1, characterized in that: The diameter length of the first segment is not greater than the diameter length of the second segment.

5. The endoluminal stent according to any one of claims 1 to 4, characterized in that: The first tube body further includes a transition section connecting the first section and the second section, and a shortening rate of the transition section is greater than a shortening rate of the first section.

6. The endoluminal stent according to any one of claims 1 to 4, characterized in that: The second tube includes an opening, and the opening faces an end of the first tube away from the second segment.

7. The endoluminal stent according to claim 6, characterized in that: The end of the first segment away from the second segment exceeds the end of the opening of the second tube by 10 to 15 mm.

8. The endoluminal stent according to any one of claims 1 to 4, characterized in that: The first tube body includes a coating and a bare stent connected to the coating, the coating includes a first coating arranged on the first segment and a second coating arranged on the second segment, the bare stent includes a first radial support structure arranged on the first segment and a second radial support structure arranged on the second segment, the first radial support structure is connected to the first coating, and the second radial support structure is connected to the second coating.

9. The endoluminal stent according to claim 8, characterized in that: The first radial support structure includes a mesh structure formed by connecting a plurality of first wavy rings in the axial direction, and the second radial support structure includes a mesh structure formed by connecting a plurality of second wavy rings in the axial direction. The number of crests and troughs of the first wavy rings and the second wavy rings are equal.

10. The endoluminal stent according to claim 8, 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, 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 along 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, the second inner film and the second outer film are both long cylindrical structures, and the axial length of the second inner film and the second outer film along the second radial support structure is equal to the axial length of the second segment.

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