Covered stent

Abstract

The invention is suitable for the field of medical instruments, and discloses a covered stent which comprises a main body section, a middle section and a far-end section. The middle section comprises a first channel and a second channel which are arranged in parallel, and the near end of the first channel and the near end of the second channel both communicate with the body section. And the far-end section is communicated with the far-end side of the first channel. Wherein the far-end section is provided with a plurality of wave rings arranged in the axial direction of the far-end section, the wave rings comprise first wave rings, at least one first wave ring is arranged at the position, connected with the first channel, of the far-end section, and the structures of the first wave rings are different from those of other wave rings in the wave rings. According to the covered stent, branch arteries can be synchronously reconstructed under the condition that aortic aneurysm is treated, and the supporting performance of the whole blood vessel can be improved.

Description

Technical Field

[0001] This application relates to the field of medical devices, and particularly to a covered stent. Background Art

[0002] Aortic diseases such as aortic aneurysms are one of the most fatal and difficult-to-treat vascular surgery diseases. In recent years, a minimally invasive and simple interventional surgical method has been developed. A covered stent is implanted at the diseased blood vessel site, and the covered stent adheres closely to the inner wall of the blood vessel, isolating the diseased part of the blood vessel from the blood flow. The covered stent can not only allow the blood to flow normally, but also protect the diseased blood vessel to effectively repair the blood vessel lesion. In the case of the existence of blood vessel branches, the covered stent also needs to be provided with branch channels to ensure that the blood can flow along the main blood vessel channel and also flow to the branch blood vessels.

[0003] When the covered stent is implanted into the blood vessels in the diseased area of the human body, in the case of treating the main cavity aneurysm, the collateral artery can be reconstructed synchronously. However, due to the huge differences in the blood vessel morphology in different parts of the human body, when the main blood vessel channel is compressed, the covered stent cannot ensure good blood flow patency. Summary of the Invention

[0004] The purpose of this application is to provide a covered stent, which aims to improve the support for various blood vessels to ensure smooth blood flow.

[0005] To achieve the above purpose, this application provides a covered stent, which is characterized in that it includes:

[0006] A main body section;

[0007] An intermediate section, the intermediate section includes a first channel and a second channel arranged in parallel, and the proximal ends of the first channel and the second channel are both communicated with the main body section;

[0008] A distal section, the distal section is communicated with the distal side of the first channel;

[0009] Wherein, the distal section is provided with a plurality of corrugated loops arranged along its axial direction, the plurality of corrugated loops include a first corrugated loop, at least one first corrugated loop is provided at least at the position where the distal section is connected to the first channel, and the first corrugated loop has a different structure from other corrugated loops among the plurality of corrugated loops.

[0010] In one embodiment, there is a gap between the first corrugated loop and the distal end of the first channel.

[0011] In one embodiment, the distal section and the first channel have the same diameter, the distal end of the first channel is provided with an inclined opening, the inclined opening is inclined towards the second channel in the direction from the proximal end to the distal end, and along the direction from the first channel to the second channel of the first corrugated loop, the wave height of the first corrugated loop gradually decreases.

[0012] In one embodiment, the first wave loop is disconnected on one side towards the second channel to form an open-loop wave loop.

[0013] In one embodiment, the diameter of at least a part of the distal segment is greater than the diameter of the distal side of the first channel. The distal segment includes a diameter-changing segment, and the diameter of the diameter-changing segment gradually increases in the proximal-to-distal direction. At least one of the first wave loops is provided on the diameter-changing segment.

[0014] In one embodiment, in the proximal-to-distal direction of the diameter-changing segment, the diameter of the diameter-changing segment gradually increases in a direction away from the second channel.

[0015] In one embodiment, in the proximal-to-distal direction of the diameter-changing segment, the diameter of the diameter-changing segment gradually increases in a direction towards the second channel.

[0016] In one embodiment, the diameter-changing segment has a concave first arc surface towards the second channel.

[0017] In one embodiment, at least one of the first wave loops is disconnected at the first arc surface to form an open-loop wave loop.

[0018] In one embodiment, the distal side of the second channel bends or inclines in a direction away from the first channel. At least one second wave loop is provided at the distal end of the second channel, and one side of at least one of the second wave loops facing away from the first channel is disconnected to form an open-loop wave loop.

[0019] For the covered stent provided in the present application, the proximal end of the main body segment can be placed in the healthy anchoring area proximal to the aortic aneurysm, the middle segment is placed in the aneurysm cavity segment of the aortic aneurysm, and the distal end of the distal segment is placed in one of the branch arteries. The operator can release the branch channel stent at the second channel, and the distal end of the branch channel stent is anchored in the other branch artery. In this way, the covered stent and the branch channel stent can well isolate the entire aneurysm cavity, thereby achieving the treatment effect. In this embodiment, the distal segment can be designed in different shapes according to the blood vessel morphology to adapt to the aneurysm cavity under various extreme conditions, thereby improving the treatment effect. Moreover, on the basis of being supported by multiple wave loops, the distal segment also has a first wave loop with a different structure at the connection position with the first channel. In this way, at least one first wave loop can also be used to stably support the connection position between the distal segment and the first channel. Therefore, the covered stent can improve the overall support for the blood vessel, so that when the blood vessel is squeezed, the covered stent still has good channel retention, thereby ensuring smooth blood flow. Description of the Drawings

[0020] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0021] Figure 1 It is one of the schematic structural diagrams of the covered stent provided by the embodiment of the present application;

[0022] Figure 2 It is another schematic structural diagram of the covered stent provided by the embodiment of the present application;

[0023] Figure 3 It is the third schematic structural diagram of the covered stent provided by the embodiment of the present application;

[0024] Figure 4 It is the fourth schematic structural diagram of the covered stent provided by the embodiment of the present application;

[0025] Figure 5 It is the schematic diagram of the axial direction of the first wave ring of the covered stent provided by the embodiment of the present application;

[0026] Figure 6 It is the fifth schematic structural diagram of the covered stent provided by the embodiment of the present application;

[0027] Figure 7 It is one of the schematic diagrams of the implanted state of the covered stent provided by the embodiment of the present application;

[0028] Figure 8 It is the sixth schematic structural diagram of the covered stent provided by the embodiment of the present application;

[0029] Figure 9 It is the seventh schematic structural diagram of the covered stent provided by the embodiment of the present application;

[0030] Figure 10 It is the eighth schematic structural diagram of the covered stent provided by the embodiment of the present application;

[0031] Figure 11 It is one of the schematic diagrams of the axial direction of the variable diameter section of the covered stent provided by the embodiment of the present application;

[0032] Figure 12 It is the ninth schematic structural diagram of the covered stent provided by the embodiment of the present application;

[0033] Figure 13 It is another schematic diagram of the implanted state of the covered stent provided by the embodiment of the present application;

[0034] Figure 14It is the second axial schematic diagram of the variable-diameter section of the covered stent provided by the embodiment of the present application;

[0035] Figure 15 It is the tenth structural schematic diagram of the covered stent provided by the embodiment of the present application;

[0036] Figure 16 It is the eleventh structural schematic diagram of the covered stent provided by the embodiment of the present application;

[0037] Figure 17 It is the twelfth structural schematic diagram of the covered stent provided by the embodiment of the present application.

[0038] Explanation of the reference numerals in the drawings:

[0039] 100: Covered stent;

[0040] 10: Main body section;

[0041] 20: Intermediate section; 21: First channel; 22: Second channel; 221: Second corrugated ring;

[0042] 30: Distal section; 301: Variable-diameter section; 3011: First arc surface; 3012: Second arc surface;

[0043] 302: Anchoring section; 31: Corrugated ring; 311: First corrugated ring;

[0044] 200: Branch channel stent;

[0045] 300: Aorta;

[0046] 400: Branch artery;

[0047] 500: Guide wire. Detailed implementation manners

[0048] Hereinafter, the exemplary embodiments of the present application will be described in more detail with reference to the drawings. Although the exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present application can be more thoroughly understood and the scope of the present application can be completely conveyed to those skilled in the art.

[0049] It should be understood that the terms used herein are for the purpose of describing particular example embodiments only and are not intended to be limiting. Unless the context clearly dictates otherwise, the singular forms "a", "an", and "the" as used herein may also include the plural forms. The terms "comprising", "including", "containing", and "having" are inclusive and thus specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order described or illustrated, unless explicitly indicated as an order of performance. It should also be understood that additional or alternative steps may be used.

[0050] Although the terms first, second, third, etc. may be used herein to describe multiple elements, components, regions, layers, and / or sections, these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or section from another. Unless the context clearly indicates otherwise, terms such as "first", "second", and other numerical terms when used herein do not imply an order or sequence. Thus, a first element, component, region, layer, or section discussed below may be referred to as a second element, component, region, layer, or section without departing from the teachings of the example embodiments.

[0051] For ease of description, spatial relative relationship terms may be used herein to describe the relationship of one element or feature shown in the figures to another element or feature, such as "inner", "outer", "inside", "outside", "below", "beneath", "above", "over", etc. Such spatial relative relationship terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is flipped, an element described as "below" or "beneath" another element or feature will then be oriented "above" or "over" the other element or feature. Thus, the example term "below" can include both an orientation above and below. The device may be otherwise oriented (rotated 90 degrees or in other directions) and the spatial relative relationship descriptors used herein are to be interpreted accordingly.

[0052] For a clearer description of the structure of the present application, the terms "proximal" and "distal" are herein defined as terms commonly used in the field of interventional medicine. Specifically, "distal" refers to the end away from the operator during a surgical procedure, "proximal" refers to the end close to the operator during a surgical procedure, "axial" refers to its length direction, and "radial" refers to the direction perpendicular to the "axial" direction.

[0053] The following will describe in detail some embodiments of the present application in conjunction with the accompanying drawings. Without conflict, the following embodiments and the features in the embodiments may be combined with each other.

[0054] As Figure 1 shown, the covered stent 100 provided in the embodiment of the present application includes a main body section 10, an intermediate section 20, and a distal section 30.

[0055] The intermediate section 20 includes a first channel 21 and a second channel 22 arranged in parallel. The proximal ends of the first channel 21 and the second channel 22 are both communicated with the main body section 10. The distal section 30 is communicated with the distal side of the first channel 21. Among them, the distal section 30 is provided with a plurality of corrugations 31 arranged along its axial direction. The plurality of corrugations 31 include at least one first corrugation 311. At least one first corrugation 311 is provided at the position where the distal section 30 is at least communicated with the first channel 21. The first corrugation 311 has a different structure from the other corrugations 31 in the plurality of corrugations 31.

[0056] It should be noted that after the covered stent 100 is implanted at the lesion site, the distal side of the second channel 22 is aligned with the opening of the branch artery 400. The operator also needs to release the branch channel stent 200 at the second channel 22 through the second channel 22, so that the aorta 300 can communicate with the branch artery 400 to ensure that blood can flow to the branch artery 400. In this embodiment, the support strength of the first channel 21 needs to be greater than that of the second channel 22. This is because the second channel 22 is the anchoring area of the branch channel stent 200. After the branch channel stent 200 is implanted, there will be two layers of stents, namely the branch channel stent 200 and the second channel 22, with a relatively strong radial support force. Therefore, the intermediate section 20 is designed in a split manner, that is, it is designed into the first channel 21 and the second channel 22 with different radial support forces. The first channel 21 with a larger radial support force can ensure a stronger support effect of the first channel 21, and the second channel 22 is beneficial to the implantation of the branch channel stent 200. Exemplarily, corrugations are also provided in the first channel 21 to ensure the support of the first channel 21.

[0057] It should be noted that the first wave loop 311 mentioned here has a different structure from the other wave loops 31 among the multiple wave loops 31, including different waveform shapes of the wave loops 31, different diameters of the wave loops 31, etc. By setting the first wave loop 311 with a different structure, it is intended to enhance the support at the connection position between the distal segment 30 and the first channel 21 and ensure smooth blood flow between the first channel 21 and the distal segment 30. Generally, the other wave loops 31 among the multiple wave loops 31 are mainly distributed on the distal side of the distal segment 30. This part of the distal segment 30 is generally placed in a healthy blood vessel. In order to anchor on the blood vessel wall and maintain support at the same time, the structures of the other wave loops 31 among the multiple wave loops 31 are the same. For example, the waveform shapes of the other wave loops 31 among the multiple wave loops 31 are the same, the diameters of the wave loops 31 are the same, etc.

[0058] For the covered stent 100 of the present application, the proximal end of the main body segment 10 can be placed in the healthy anchoring area proximal to the aortic aneurysm 300, the middle segment 20 is placed in the aneurysm cavity segment of the aortic aneurysm 300, and the distal side of the distal segment 30 is placed in one of the branch arteries 400. The operator can release the branch channel stent 200 at the second channel 22, and the distal end of the branch channel stent 200 is anchored in another branch artery 400. In this way, the covered stent 100 and the branch channel stent 200 can well isolate the entire aneurysm cavity, thereby achieving the treatment effect. In this embodiment, the distal segment 30 can be designed in different shapes according to the blood vessel morphology to adapt to the aneurysm cavity under various extreme conditions, thereby improving the treatment effect. Moreover, on the basis of being supported by multiple wave loops 31, the distal segment 30 is also provided with a first wave loop 311 with a different structure at the connection position with the first channel 21. In this way, the stable support of the connection position between the distal segment 30 and the first channel 21 can also be realized through at least one first wave loop 311. Therefore, the covered stent 100 can improve the overall support for the blood vessel, so that when the blood vessel is squeezed, the covered stent 100 still has good channel retention, and further ensure smooth blood flow.

[0059] The covered stent 100 of the present application can synchronously reconstruct the branch artery 400 in the case of treating the aortic aneurysm 300, ensure adaptation to the blood vessel morphology, and ensure smooth blood flow. Its indications include, but are not limited to, situations where branch arteries 400 such as the left and right subclavian arteries, common carotid arteries, and internal iliac arteries need to be reconstructed. Especially for the aneurysm cavity of the common iliac artery, internal iliac artery, and external iliac artery. Specifically, the iliac artery includes the common iliac artery, external iliac artery, and internal iliac artery. The morphology of this part of the artery is complex and twisted. The patency of the blood flow in the external iliac artery channel is far more important than that in the internal iliac artery channel. Therefore, through the design of the distal segment 30 of the present application, the priority of the external iliac artery can be ensured, and the patency of the external iliac lumen can be ensured under complex conditions. At the same time, while meeting its priority, by establishing the branch channel stent 200, the normal function of the internal iliac artery will not be affected.

[0060] As Figure 2 shown, in some embodiments, there is a gap between the first corrugated ring 311 and the distal end of the first channel 21. It should be noted that the gap between the first corrugated ring 311 and the distal end of the first channel 21 refers to the gap from the peak of the first corrugated ring 311 to the distal end of the first channel 21. It should be known that if there is no gap between the first corrugated ring 311 and the distal end of the first channel 21, the peak of the first corrugated ring 311 will be sewn to the distal end of the first channel 21. In this state, the membrane between the distal segment 30 and the first channel 21 will be stretched by the first corrugated ring 311. When the distal segment 30 is twisted, the membrane will be driven to stretch, and the flexibility will be very poor; moreover, the membrane in the direction opposite to the twisting direction of the distal segment 30 will be stretched, and the suture holes at the peak of the first corrugated ring 311 may be elongated and enlarged, increasing the risk of stent leakage. In this embodiment, by setting a gap between the first corrugated ring 311 and the distal end of the first channel 21, there is enough gap membrane between the distal segment 30 and the distal end of the first channel 21, so that when the distal segment 30 is twisted, the membrane between the distal segment 30 and the first channel 21 can deform accordingly, so as to improve the flexibility when the distal segment 30 is twisted. At the same time, since the first corrugated ring 311 and the first channel 21 are not connected, the risk of leakage caused by the twisting of the distal segment 30 can also be avoided. In this embodiment, the gap between the first corrugated ring 311 and the distal end of the first channel 21 should not be too large. When the distal segment 30 bends towards the second channel 22, too large a gap will cause the distal segment 30 to bend, and the peak of the first corrugated ring 311 will enter the gap membrane, thus affecting the patency of the distal segment 30.

[0061] Exemplarily, the gap between the first corrugated ring 311 and the distal end of the first channel 21 can be adjusted according to the flexibility requirement of the distal segment 30. When the covered stent 100 is applied to the iliac artery, the gap is estimated according to the vascular twisting morphology of the iliac artery. For example, the gap can be 0.5 mm - 2 mm.

[0062] As Figures 1 to 4As shown, in some embodiments, the distal segment 30 and the first channel 21 have the same diameter. An inclined opening is provided at the distal end of the first channel 21. The inclined opening is inclined towards the second channel 22 in the direction from the proximal end to the distal end. Along the direction from the first channel 21 to the second channel 22, the wave height of the first wave loop 311 gradually decreases to match the inclined opening. Through the provided inclined opening, when the distal segment 30 bends away from the second channel 22, the inclined opening can well conform to the blood vessel morphology and increase the flexibility of the bending of the distal segment 30. The fact that the first wave loop 311 set in this embodiment gradually becomes smaller means that the waveform of the first wave loop 311 gradually becomes smaller. That is to say, the wave loop of the first wave loop 311 far from the second channel 22 is a high wave, and the wave loop close to the second channel 22 is a low wave. The high and low waves are arranged along the height of the inclined opening to match the inclined opening. The first wave loop 311 can conform to the membrane at the distal end of the first channel 21, so that the position where the distal segment 30 is connected to the first channel 21 has better bending and anti-folding performance.

[0063] Exemplarily, there is a gap between the first wave loop 311 and the inclined opening.

[0064] Exemplarily, in the distal segment 30, the distance between the first wave loop 311 and other adjacent wave loops 31 among the plurality of wave loops 31 is the same as the distance between other wave loops 31 among the plurality of wave loops 31. In this way, the overall distal segment 30 can have better support to ensure smooth blood flow.

[0065] Exemplarily, when the first wave loop 311 is not disconnected, the low wave on the side of the first wave loop 311 facing the second channel 22 is the wave trough. In this way, when the bending of the distal segment 30 towards the second channel 22 reaches the limit, the situation that the inclined opening is deformed due to the influence of the low wave of the first wave loop 311 can be avoided, and thus the flexibility of the bending of the distal segment 30 can be improved.

[0066] As Figures 1 to 4 shown, in some embodiments, an inclined opening is provided at the distal end of the second channel 22. The inclined opening is inclined towards the first channel in the direction from the proximal end to the distal end. Through the provided inclined opening, it is more conducive to the release of the branch channel stent 200 at the second channel 22.

[0067] As Figure 3 and Figure 4As shown, in some embodiments, the first wave loop 311 is disconnected on one side facing the second channel 22 to form an open-loop wave loop. It should be noted that if the first wave loop 311 is not disconnected, when the distal segment 30 bends towards the second channel 22, the wave crest of the low wave on the side of the first wave loop 311 facing the second channel 22 will abut against the beveled opening. When the bending reaches the limit, the beveled opening will be deformed due to the influence of the wave crest of the low wave, resulting in poor morphology at the beveled opening, and further possibly leading to leakage or poor blood flow at the beveled opening. In this embodiment, by disconnecting the first wave loop 311 on the side facing the second channel 22, when the distal segment 30 bends towards the second channel 22, whether the low wave on the side of the first wave loop 311 facing the second channel 22 is a trough or a crest, the situation where the beveled opening is deformed due to the influence of the first wave loop 311 can be avoided, thus improving the flexibility of the bending of the distal segment 30.

[0068] Exemplarily, as Figure 4 and Figure 5 shown, the end of the first wave loop 311 at the fracture is curled to form a C-shaped wave. In this way, while avoiding interfering with the bending of the distal segment 30, the first wave loop 311 can also maintain a certain supporting force. For example, the end of the first wave loop 311 at the fracture bends towards the direction of the first channel 21 to form a C-shaped wave.

[0069] As Figure 6 shown, in some embodiments, the diameter of at least a part of the distal segment 30 is greater than the diameter of the distal side of the first channel 21. Specifically, the diameter of the distal segment 30 is greater than that of the first channel 21. The distal segment 30 includes a diameter-changing segment 301 and an anchoring segment 302. The diameter of the diameter-changing segment 301 gradually increases in the proximal-to-distal direction. At least one first wave loop 311 is arranged according to the diameter of the diameter-changing segment 301, and at least one first wave loop 311 is provided on the diameter-changing segment 301. The morphological differences of the aortic aneurysm 300 are large. When the branch artery 400 is large and the anchoring area is very small, if the diameter of the distal segment 30 is the same as that of the first channel 21, the distal segment 30 may not be well anchored in the anchoring area, resulting in the inability to isolate the aneurysm cavity and affecting the treatment effect. In this embodiment, the diameter-changing segment 301 can achieve the diameter transition from the first channel 21 to the anchoring segment 302. Since the diameter of the anchoring segment 302 is increased, the aneurysm cavity can be isolated in the case of a large branch artery 400 and a small anchoring area to achieve the effect of treating the aortic aneurysm 300. In addition, at least one first wave loop 311 is arranged according to the diameter of the diameter-changing segment 301, which can also improve the support for the diameter-changing segment 301 and ensure smooth blood flow.

[0070] As Figure 6 shown, in some embodiments, along the proximal-to-distal direction of the diameter-changing segment 301, the diameter of the diameter-changing segment 301 gradually increases in the direction away from the second channel 22. Specifically, as Figure 6As shown, the diameter-changing section 301 changes its diameter to the left as shown in the figure and protrudes outward in the circumferential direction. The distal section 30 has completed the diameter change and can isolate the aneurysm cavity when the branch artery 400 has a large blood vessel and a small anchoring area, so as to achieve the effect of treating the aortic aneurysm 300. As Figure 7 As shown, in this embodiment, the distal section 30 increases its diameter to the left in the circumferential direction, and it will squeeze the blood vessels outside the bifurcation of the branch artery 400. Therefore, this embodiment is applicable to the situation where the aneurysm cavity is spacious and allows the distal section 30 to increase its diameter outward, which is the most commonly used situation clinically. In this embodiment, the diameter-changing section 301 is located in the aortic aneurysm cavity 300. If the branch-channel stent 200 of the second channel 22 is released, the volume of the covered stent 100 and the branch-channel stent 200 in the diameter-changing section 301 will be the stent volume with a diameter of D2 + D3, where D2 is the diameter of the anchoring section 302 and D3 is the diameter of the branch-channel stent 200. The length L1 between the starting position of the diameter-changing section 301 and the main body section 10 can be determined according to the situation of the aneurysm cavity, which affects the covered distance in the aneurysm cavity, and the distance L1 can be adjusted according to actual requirements. Generally speaking, the length of L1 is between 0 and 25 mm. When L1 = 0 mm, the volume of the middle section 20 reaches the maximum, which is applicable to the situation where the distal aortic aneurysm cavity 300 is greatly dilated and needs to be filled.

[0071] Exemplarily, as Figure 6 shown, due to the small blood vessel anchoring area, the proximal end of the distal section 30 starts to change its diameter from the beveled opening of the first channel 21 and transitions obliquely until it changes to the anchoring section 302.

[0072] As Figure 8 shown, in some embodiments, along the direction from the proximal end to the distal end of the diameter-changing section 301, the diameter of the diameter-changing section 301 gradually increases in the direction of the second channel 22. Specifically, as Figure 8 shown, the diameter-changing section 301 changes its diameter to the right as shown in the figure and protrudes outward in the circumferential direction. The distal section 30 has completed the diameter change and can isolate the aneurysm cavity when the branch artery 400 has a large blood vessel and a small anchoring area, so as to achieve the effect of treating the aortic aneurysm 300. In this embodiment, when the covered stent 100 is implanted in the body, it will not squeeze the blood vessels outside the bifurcation of the branch artery 400, and has lower requirements for the aneurysm cavity while achieving the treatment effect. In addition, since the distal section 30 increases its diameter to the right, it will squeeze the branch-channel stent 200. Therefore, this solution is applicable to the situation where the aneurysm cavity is crowded, the release condition of the covered stent 100 is poor, and the branch artery 400 has a slightly smaller blood vessel and allows a certain degree of compression. In this embodiment, the length L2 between the starting position of the diameter-changing section 301 and the main body section 10 can be set according to the specific situation of the aneurysm cavity, which affects the distance at which the distal section 30 squeezes and compresses the branch-channel stent 200, and the distance L2 can be adjusted according to actual requirements. Generally speaking, the length of L2 > 20 mm, and the specific length can be set according to the volume of the aneurysm cavity section.

[0073] Exemplarily, as Figure 8 shown, the proximal end of the distal segment 30 starts to change in diameter from the beveled distal end of the first channel 21, showing an inclined transition until it changes in diameter to the anchoring segment 302.

[0074] As Figure 9 shown, in some embodiments, along the direction from the proximal end to the distal end of the diameter-changing segment 301, the diameter of the diameter-changing segment 301 gradually increases in the direction away from the second channel 22, and at the same time, the diameter of the diameter-changing segment 301 gradually increases in the direction towards the second channel 22. Specifically, as Figure 9 shown, the diameter-changing segment 301 protrudes outwards in a full circumferential circle. The distal segment 30 has completed the diameter change, and can isolate the aneurysm cavity in the case where the branch artery 400 is large and the anchoring area is small, so as to achieve the effect of treating the aortic aneurysm 300. In this embodiment, the distal segment 30 increases in diameter both towards the left and towards the right in the circumferential direction, and both sides of the distal segment 30 can evenly distribute the pressure of the first channel 21, reducing the requirements for the aneurysm cavity of the covered stent 100. In this embodiment, the length L1 between the starting position on the left side of the diameter-changing segment 301 and the main body segment 10, and the length L2 between the starting position on the right side of the diameter-changing segment 301 and the main body segment 10 can refer to the above embodiments and be set according to the specific situation of the aneurysm cavity, which will not be elaborated.

[0075] Exemplarily, as Figure 9 shown, due to the small vascular anchoring area, the proximal end of the distal segment 30 starts to change in diameter from the beveled opening of the first channel 21, showing an inclined transition until it changes in diameter to the anchoring segment 302.

[0076] As Figures 6 to 9 shown, in some embodiments, when the difference between the diameter D2 of the distal segment 30 and the diameter D1 of the main body segment 10 is small, for example, when 0 mm < D2 - D1 < 4 mm, the compression of the distal segment 30 is less obvious, and usually the conditions of the aneurysm cavity or the branch artery 400 can be satisfied. The covered stent 100 with the diameter change of the distal segment 30 as described above can be selected for treatment according to the actual situation; when the difference between the diameter D2 of the distal segment 30 and the diameter D1 of the main body segment 10 is large, for example, when 4 mm < D2 - D1 < 8 mm, the covered stent 100 with the full circumferential diameter change of the distal segment 30 as described above can be selected, and the increased diameter size can be determined according to the actual situation of the patient, so as to further reduce the requirements for the aneurysm cavity and greatly enhance the adaptability.

[0077] As Figure 10 and Figure 11As shown, in some embodiments, in the direction from the proximal end to the distal end of the diameter-changing section 301, at least one first corrugated ring 311 is radially distributed on the axial projection plane of the distal section 30 and is adapted to the axial projection plane of the distal section 30. The first corrugated ring 311 arranged in this way can improve the support of the diameter-changing section 301 to ensure smooth blood flow. Specifically, on the axial projection plane of the distal section 30, as the diameter increases, the waveform of the first corrugated ring 311 also increases. For example, when the diameter of the diameter-changing section 301 increases towards the left, on the axial projection plane of the distal section 30, the first corrugated ring 311 has a high wave on the left and a low wave on the right.

[0078] Exemplarily, as Figure 11 shown, when multiple first corrugated rings 311 are arranged on the diameter-changing section 301, the wave peaks and wave valleys of adjacent corrugated rings 31 are arranged correspondingly to provide better support for the diameter-changing section 301. For example, in the direction from the proximal end to the distal end of the diameter-changing section 301, two first corrugated rings 311 with gradually increasing diameters are arranged on the diameter-changing section 301.

[0079] Exemplarily, as Figure 10 shown, the first corrugated ring 311 of the diameter-changing section 301 close to the first channel 21 is arranged along the distal end of the first channel 21. In this way, the first corrugated ring 311 can stably support the connection position between the diameter-changing section 301 and the first channel 21 to increase the bending and anti-folding performance between the first channel 21 and the distal section 30.

[0080] As Figure 12 and Figure 13 shown, in some embodiments, the diameter-changing section 301 has an inwardly concave first arc surface 3011 facing the second channel 22. When threading the guide wire 500 through the second channel 22, the first arc surface 3011 can provide guidance for the guide wire 500 so that the guide wire 500 can smoothly penetrate into the branch blood vessel to reduce the surgical risk. Specifically, as Figure 12 shown, the diameter-changing section 301 changes in diameter towards the right as shown in the figure and protrudes outward in the circumferential direction. In order to form the first arc surface 3011 of this embodiment, at least one first corrugated ring 311 is designed as a radially special corrugated ring with an inwardly concave arc. The first arc surface 3011 is obtained through the support of at least one first corrugated ring 311. After the covered stent 100 is implanted, the first arc surface 3011 is in the transition area between the aortic aneurysm cavity 300 and the anchoring area of the branch artery 400. When threading the guide wire 500 through the second channel 22, the first arc surface 3011 can guide the soft tip of the guide wire 500 to make the threading of the guide wire 500 smoother and simpler.

[0081] Exemplarily, as Figure 14As shown, on the first arc surface 3011, the first wave loop 311 has a wave trough on the side facing the second channel 22. Specifically, when the first wave loops 311 are radially distributed on the axial projection plane of the distal segment 30, the largest wave loop 31 corresponding to the diameter-increasing part of the diameter-changing segment 301 is set as the wave trough. In this way, in cooperation with the radian design of the first arc surface 3011, the influence on the threading of the guide wire 500 can be further reduced, avoiding the guide wire 500 being stuck in the first wave loop 311, and making the threading of the guide wire 500 smoother.

[0082] As Figure 15 shown, in some embodiments, at least one first wave loop 311 is disconnected at the first arc surface 3011 to form an open-loop wave loop. It should be noted that when the first wave loop 311 is not disconnected, regardless of whether the side of the first wave loop 311 facing the second channel 22 is a wave trough or a wave peak, when the guide wire abuts against the first arc surface 3011, the first wave loop 311 may impede the movement of the guide wire 500. In this embodiment, however, by disconnecting the first wave loop 311 at the first arc surface 3011, the obstructive wave loop on the threading path of the soft tip of the guide wire 500 is removed, leaving only the stent membrane in this part, improving the surface smoothness of the guide wire during sliding after abutment, which is beneficial to the threading of the guide wire 500. At the same time, the flexibility of the distal segment 30 during bending is also improved.

[0083] Exemplarily, as Figure 15 shown, the end of the first wave loop 311 at the break is curled to form a protective head end without sharp objects. In this way, while being beneficial to the threading of the guide wire 500, the first wave loop 311 maintains a certain supporting force to ensure the overall support of the distal segment 30. Further, the end of the first wave loop 311 at the break bends away from the break to form a protective head end, which can avoid the protective head end at the break affecting the movement trajectory of the guide wire 500, and the protective head end away from the break will not push against the surface film, preventing the break of the first wave loop 311 from piercing the film and damaging the blood vessel.

[0084] As Figure 16As shown, in some embodiments, the distal end of the second channel 22 is bent or inclined away from the first channel 21. At least one second corrugation 221 is provided at the distal end of the second channel 22. One side of at least one second corrugation 221 facing away from the first channel 21 is disconnected to form an open-loop corrugation. Through the special second corrugation 221, the distal end of the second channel 22 is supported, so that the distal end of the second channel 22 can be bent or inclined. In this embodiment, by bending or inclining the distal end of the second channel 22 away from the first channel 21, when threading the guide wire 500, the bending or inclining state of the distal end of the second channel 22 can guide the guide wire 500 before the guide wire exits the second channel 22, further reducing the difficulty of threading the guide wire 500, so that the guide wire 500 can enter the branch artery 400 more smoothly, which is beneficial to the implantation of the branch channel stent 200.

[0085] Exemplarily, as Figure 16 shown, the radian of the distal end of the second channel 22 bent away from the first channel 21 is the same as the radian direction of the first arc surface 3011. Through the guidance of the first arc surface 3011 and the distal end of the second channel 22, the difficulty of threading the guide wire 500 is further reduced.

[0086] As Figure 16 shown, in some embodiments, one side of the first corrugation 311 facing away from the first channel 21 is disconnected to form an open-loop corrugation. In this way, when threading the guide wire 500, the obstructive corrugation on the threading path of the soft tip of the guide wire 500 is removed, so that only the stent membrane remains in this part, which is beneficial to the threading of the guide wire 500.

[0087] Exemplarily, the end of the second corrugation 221 at the fracture is curled to form a protective head end without sharp objects. In this way, while being beneficial to the threading of the guide wire 500, the second corrugation 221 can also maintain a certain supporting force to ensure the support of the distal end of the second channel 22. Further, the end of the second corrugation 221 at the fracture is bent away from the fracture to form a protective head end. In this way, it can be avoided that the protective head end at the fracture affects the movement track of the guide wire 500, and the protective head end away from the fracture will not touch the surface coating film, and the fracture of the second corrugation 221 can be prevented from piercing the coating film and damaging the blood vessel.

[0088] As Figure 17As shown, in some embodiments, the diameter-changing section 301 has a second arc surface 3012 with an outer protrusion facing the second channel 22. When the guide wire 500 is inserted, since the second arc surface 3012 is closer to the outlet of the second channel 22, the guide wire 500 can contact the second arc surface 3012 earlier, and under the guidance of the second arc surface 3012, the guide wire 500 can smoothly penetrate into the branch blood vessel to reduce the surgical risk. In order to form the second arc surface 3012 of this embodiment, the first wave loop 311 can be shaped into a convex shape through a heat setting process, and then covered or sewn on the membrane through a film covering heat treatment or a sewing process to support the membrane.

[0089] Exemplarily, as Figure 17 shown, on the second arc surface 3012, the side of the first wave loop 311 facing the second channel 22 is a wave valley. Specifically, when the first wave loops 311 are radially distributed on the axial projection plane of the distal section 30, the largest wave loop 31 corresponding to the diameter-increasing part of the diameter-changing section 301 is set as the wave valley. In this way, in cooperation with the arc design of the second arc surface 3012, the influence on the penetration of the guide wire 500 can be further reduced, and the guide wire 500 can be prevented from being stuck in the first wave loops 311, making the penetration of the guide wire 500 smoother.

[0090] The above are only the preferred embodiments of the present application, and do not limit the patent scope of the present application accordingly. Any equivalent structural transformation made by using the content of the specification and drawings of the present application under the application concept of the present application, or any direct / indirect application in other related technical fields is included in the patent protection scope of the present application.

Claims

1. A stent graft, characterized in that: include: The main body paragraph; A middle section, the middle section comprising a first channel and a second channel arranged in parallel, wherein the proximal ends of the first channel and the second channel are both connected to the main section; a distal section, the distal section being connected to the distal side of the first channel; Among them, the distal section is provided with multiple wave coils arranged along its axial direction, and the multiple wave coils include a first wave coil. At least one of the first wave coils is provided at the position where the distal section is connected to at least the first channel, and the first wave coil has a different structure from other wave coils in the multiple wave coils.

2. A stent graft according to claim 1, characterized in that: A gap is provided between the first wave ring and a distal end of the first channel.

3. The stent graft according to claim 1, characterized in that: The distal section and the first channel have the same diameter, the distal end of the first channel is provided with an oblique opening, the oblique opening is inclined toward the second channel along the direction from the proximal end to the distal end, and the wave height of the first wave circle gradually decreases along the direction from the first channel to the second channel.

4. A stent graft according to claim 3, characterized in that: The first coil is disconnected toward one side of the second channel to form an open-loop coil.

5. The stent graft according to claim 1, characterized in that: The diameter of at least a portion of the distal section is larger than the diameter of the distal side of the first channel. The distal section includes a diameter-reducing section whose diameter gradually increases from the proximal end to the distal end. At least one of the first wave rings is arranged on the diameter-reducing section.

6. The stent graft according to claim 5, characterized in that: Along the direction from the proximal end to the distal end of the diameter-changing section, the diameter of the diameter-changing section gradually increases in a direction away from the second channel.

7. The stent graft according to claim 5, characterized in that: Along the direction from the proximal end to the distal end of the diameter-changing section, the diameter of the diameter-changing section gradually increases toward the second channel.

8. The stent graft according to claim 7, characterized in that: The diameter-changing section has a first arc-shaped surface which is concave toward the second channel.

9. The stent graft according to claim 8, characterized in that: At least one of the first wave coils is disconnected at the first arc-shaped surface to form an open-loop wave coil.

10. The stent graft according to claim 1, characterized in that: The distal end of the second channel is bent or inclined in a direction away from the first channel. The distal end of the second channel is provided with at least one second wave coil. The at least one second wave coil is disconnected at a side away from the first channel to form an open-loop wave coil.

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