Covered stent and stent system

Abstract

Provided are a covered stent (10) and a stent system. The covered stent (10) comprises a main body stent (11), a branch stent (12), and a connecting membrane tube (13). The branch stent (12) comprises a circumferential connection (121). The circumferential connection (121) comprises a first connection point (121a), and the first connection point (121a) is closest in an axial direction to a distal end of the covered stent (10). The covered stent (10) further comprises a first axial line (15) and a second axial line parallel to a longitudinal central axis of the main body stent (11). The first axial line (15) passes through the first connection point (121a), and the first axial line (15) further intersects the circumferential connection (121) at a second connection point (121b). The second axial line intersects a window (113) at a third connection point (113a) and a fourth connection point (113b), and the third connection point (113a) is located on the distal-end side of the fourth connection point (113b). The axial distance between the first connection point (121a) and the third connection point (113a) is less than the axial distance between the second connection point (121b) and the fourth connection point (113b). According to the covered stent (10), when a branch is constructed, the entire released covered stent (10) can be prevented from moving backward, thereby avoiding the problem of insufficient anchoring at the proximal end of the released main body stent (11).

Description

Covered stents and stent systems Technical Field

[0001] This invention relates to the field of medical devices, and in particular to a covered stent and stent system. Background Technology

[0002] Aortic aneurysms and aortic dissections are serious diseases that threaten human life. Without prompt treatment, these aneurysms and dissections will continue to grow, eventually rupturing and causing severe complications and death. With the increasing number of patients with hypertension, hyperlipidemia, and hyperglycemia, the incidence of aortic aneurysms and aortic dissections is also rising significantly. Traditional open surgery for aortic aneurysms and aortic dissections is highly invasive, has a high mortality rate, long operation time, high postoperative complication rate, and high surgical difficulty. Endovascular treatment, on the other hand, is less invasive, has fewer postoperative complications, shorter operation time, and lower surgical difficulty, and has gradually become the main method for treating aortic aneurysms and aortic dissections. By implanting a covered stent in the aorta, the vascular lesion is isolated outside the covered stent, restricting blood flow through the stent and thus protecting the blood vessel.

[0003] For covered stents with branch stents at the aortic arch, after the main stent of the covered stent naturally expands and adheres to the inner wall of the vessel, the ultra-rigid guidewire extends along the descending aorta into the branch vessel. Due to the angular relationship between the descending aorta and the branch vessel, as well as the tortuous structure of the aortic arch, during the process of constructing the branch pathway using the ultra-rigid guidewire at the branch stent, or during the implantation of the external small stent using the branch pathway formed by the ultra-rigid guidewire after the branch pathway is constructed, the free end of the branch stent is tilted towards the proximal end when the branch pathway is constructed by the ultra-rigid guidewire. Furthermore, the central axis of the existing covered stent 90 branch stent tends to be directly aligned with the window 91 used to connect the branch stent. The center (as shown in Figure 1) is designed so that after positioning using the imaging ring around the window, the branch stent can be aligned with the branch vessel orifice. However, due to the curvature of the ultra-rigid guidewire in the descending aorta, aortic arch, and branch vessels, during the delivery of the external branch using the ultra-rigid guidewire, the ultra-rigid guidewire pulls on the distal end of the main stent. This forces the main stent, causing it to be pulled along, resulting in the anchoring segment of the main stent at the proximal end shifting towards the distal end (the arrow position in Figure 3 is offset from the distal end in Figure 2). Consequently, the anchoring segment at the proximal end of the deployed main stent is not properly anchored, as shown in Figures 1-3. Summary of the Invention

[0004] At least one technical problem solved by the present invention is how to prevent the main body of the branched covered stent from being pulled and moved backward as a whole, thereby causing insufficient anchorage at the proximal end of the main body stent after it has been released.

[0005] This invention provides a covered stent, comprising a main stent, branch stents, and connecting membrane tubes. The main stent includes a window disposed on one side of the main stent, and the branch stent is connected to the window, with the lumen of the branch stent communicating with the lumen of the main stent through the window. The branch stent includes a circumferential connection, one end of the connecting membrane tube is circumferentially connected to the window, and the other end of the connecting membrane tube is circumferentially connected to the circumferential connection. The circumferential connection includes a first connection point, which is axially closest to the distal end of the covered stent. The covered stent also includes a first axial line and a second axial line parallel to the longitudinal central axis of the main stent. The first axial line passes through the first connection point and intersects the circumferential connection at a second connection point. The second axial line intersects the window at a third connection point and a fourth connection point. The third connection point is located on the distal end side of the fourth connection point. The axial distance between the first connection point and the third connection point is less than the axial distance between the second connection point and the fourth connection point.

[0006] In one embodiment, the window is circular or elliptical, the circumferential connection is circular or elliptical, and the geometric center of the circumferential connection is closer to the distal end of the lumen support than the geometric center of the window.

[0007] In one embodiment, the branch bracket includes a first end, a middle section, and a second end, wherein the first end and the second end are two ends disposed opposite to each other, the middle section is disposed between the first end and the second end, and the circumferential connection is located in the middle section.

[0008] In one embodiment, the main support includes an annular support member disposed along the edge of the window.

[0009] In one embodiment, when the circumferential connection is on the same horizontal plane as the window, the width of the connecting membrane tube in any direction is greater than the distance from the circumferential connection to the window in the same direction.

[0010] The present invention also provides a stent system comprising a covered stent and a delivery device as described above, the delivery device comprising a semi-binding structure that releasably binds the main stent to radially compress or release the main stent, the stent system further comprising an adjustable bendable conduit extending within the lumen of the main stent, the distal end of the adjustable bendable conduit entering from the distal end of the main stent and exiting from the branch stent.

[0011] In one embodiment, the adjustable bend conduit includes an adjustable bend and an adjusting member. The adjustable bend includes an extension section and an adjustable bend segment, the adjustable bend segment being disposed at the distal end of the extension section. The adjustable bend conduit also includes a limiting hole, the limiting hole being disposed at the proximal end of the adjustable bend segment. The adjusting member includes a distal end and an adjusting segment. The distal end of the adjusting member is connected to the distal end of the adjustable bend. The adjusting member passes through the limiting hole and extends towards the proximal end, thereby forming the adjusting segment between the limiting hole and the distal end. The semi-binding structure includes a wrapping member and a detachable bundle diameter member. The detachable bundle diameter member cooperates with the wrapping member to achieve radial constriction and release of the covered stent. The detachable bundle diameter member passes through the gap between the adjusting segment and the adjustable bend segment.

[0012] In one embodiment, the limiting hole includes a cavity structure extending axially, with the distal end of the limiting hole extending to the proximal side of the adjustable bend.

[0013] In one embodiment, the limiting hole is located on the wall of the adjustable bend;

[0014] Alternatively, the limiting hole is located on the outside of the adjustable bend.

[0015] In one embodiment, the adjustable bend conduit further includes a limiting buckle disposed on the distal side of the limiting hole and close to the limiting hole, such that a limiting hole is formed between the adjustable bend and the adjusting member between the limiting buckle and the distal end of the limiting hole, and the diameter detachable member can pass through the limiting hole.

[0016] One technical effect of an embodiment of the present invention is that by setting the axial distance between the first connection point and the third connection point to be smaller than the axial distance between the second connection point and the fourth connection point, the proximal edge of the branch support relative to the window is offset more towards the distal edge of the window. This avoids the bending direction of the constructed branch path pulling the branch support towards the distal end of the main support, causing the main support to be under force and causing the released main support to move backward, thereby avoiding the overall backward movement of the released covered stent and thus avoiding the problem of insufficient anchorage at the proximal end of the released main support. Attached Figure Description

[0017] Figure 1 is a schematic diagram of the structure of a membrane-covered scaffold in the prior art;

[0018] Figure 2 is a schematic diagram of a covered stent of the prior art used in the aortic arch;

[0019] Figure 3 is a schematic diagram of the main stent of the covered stent being pulled towards the distal end and moved backward relative to the main stent in Figure 2 when the covered stent is in the aortic arch in the prior art.

[0020] Figure 4 is a schematic diagram of the structure of the covered stent in one embodiment provided in this application;

[0021] Figure 5 is a structural schematic diagram of the covered stent from another perspective in one embodiment provided in this application (the covering is omitted);

[0022] Figure 6 is a top view of Figure 5 from the right side;

[0023] Figure 7 is a schematic diagram of the branch bracket in one embodiment provided in this application;

[0024] Figure 8 is a schematic diagram showing the branch stent deflected towards the proximal end relative to the branch stent in Figure 5;

[0025] Figure 9 is a partial structural schematic diagram of the film-coated support provided in one embodiment of this application (partial film coating omitted);

[0026] Figure 10 is a partial structural diagram of the cooperation between the film-coated support (partial film covering omitted) and the binding wire provided in an embodiment of this application;

[0027] Figure 11 is a planar unfolded view of the membrane provided in one embodiment of this application;

[0028] Figure 12 is a schematic diagram of the structure of the film-covered support provided in an embodiment of this application;

[0029] Figure 13 is a schematic diagram of the connection between the membrane and the main support provided in an embodiment of this application (the main membrane is omitted);

[0030] Figure 14 is a schematic diagram of the structure of a portion of the main support provided in an embodiment of this application;

[0031] Figure 15 is a structural schematic diagram of a portion of the main support provided in another embodiment of this application;

[0032] Figure 15a is a schematic diagram of the structure of a portion of the main support provided in another embodiment of this application;

[0033] Figure 16 is an enlarged view of point B in Figure 14;

[0034] Figure 17 is a schematic diagram of the support system provided in one embodiment of this application;

[0035] Figure 18 is a structural schematic diagram of the support rod provided in one embodiment of this application from an axial perspective.

[0036] Figure 19 is a schematic diagram of the structure of the covered stent being radially compressed and wrapped in a film according to one embodiment of the present application;

[0037] Figure 20 is a partial structural schematic diagram of an adjustable bendable conduit in one embodiment provided in this application;

[0038] Figure 21 is a radial cross-sectional view of Figure 20;

[0039] Figure 22 is a partial structural schematic diagram of the adjustable conduit (unadjusted state) in another embodiment provided in this application;

[0040] Figure 23 is a partial structural schematic diagram of the adjustable conduit (adjusted state) in another embodiment provided in this application;

[0041] Figure 24 is an enlarged view of point D in Figure 22;

[0042] Figure 25 is an enlarged view of point E in Figure 24;

[0043] Figure 26 is a cross-sectional view of the extension section in Figure 22;

[0044] Figure 27 is a structural schematic diagram of another embodiment of the limiting hole provided in this application;

[0045] Figure 28 is a partial structural diagram of the branch support in Figure 19;

[0046] Figure 29 is a partial structural schematic diagram of the guide head and inner sheath core provided in an embodiment of this application;

[0047] Figure 30 is a schematic diagram of the card in the post-release structure provided in an embodiment of this application;

[0048] Figure 31 is a diagram of the closable state formed by the locking of the card and the card slot of the rear-release structure provided in an embodiment of this application.

[0049] Figure 32 is a schematic diagram of the stent system provided in this application when used in the aortic arch, with the sheath withdrawn to the distal end of the covered stent, exposing the capsule and the covered stent being wrapped by the capsule and in a semi-restrained state.

[0050] Figure 33 is a schematic diagram of adjusting the adjustable segment to face the branch vessel opening (left subclavian artery) based on Figure 32;

[0051] Figure 34 is a schematic diagram of inserting an ultra-fine guidewire into the left subclavian artery to a certain length, based on Figure 33;

[0052] Figure 35 is a schematic diagram of pushing the adjustable bendable catheter forward to follow the ultra-fine guidewire into the left subclavian artery based on Figure 34, then withdrawing the ultra-fine guidewire, delivering another ultra-stiff guidewire along the adjustable bendable catheter to the left subclavian artery, and then withdrawing the bundle diameter guidewire to begin releasing the semi-restrained state of the covered stent.

[0053] Figure 36 is a schematic diagram showing how the semi-restrained state of the covered stent is released by further retracting the guide wire based on Figure 35.

[0054] Figure 37 is a schematic diagram of the delivery device for removing the adjustable bendable catheter, then the outer sheath core, releasing the release structure, and further removing the covered stent, based on Figure 36. Detailed Implementation

[0055] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0056] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "inner," "outer," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0057] "Axial direction" generally refers to the length of a medical device during delivery, while "radial direction" generally refers to the direction perpendicular to the medical device's "axial direction." Based on this principle, the "axial" and "radial" directions of any component of a medical device are defined. Furthermore, when describing luminal stents or covered stents, the orientation can be defined according to the direction of blood flow in the blood vessel. In this invention, blood flow is defined as flowing from the proximal end to the distal end of the stent. In the field of interventional medical devices, for delivery devices used to implant medical devices into humans or animals, the end closer to the operator is generally defined as the "proximal end," and the end farther from the operator is defined as the "distal end." Based on this principle, the "proximal end" and "distal end" of any component of the delivery device are defined.

[0058] The "wave loop" in this application is a closed ring structure, also known as a wave-shaped ring, made of woven or cut metallic elastic material. This metallic elastic material includes known materials used in implantable medical devices or combinations of various biocompatible materials, such as alloys of two or more single metals selected from cobalt, chromium, nickel, titanium, magnesium, and iron, as well as 316L stainless steel, nickel-titanium-tantalum alloys, or other biocompatible metallic elastic materials. The wave loop has radial expansion capability, allowing it to radially contract under external force and recover its initial shape after the external force is removed, thus maintaining its initial shape. After implantation into a lumen, its radial support force allows it to adhere tightly to the inner wall of the lumen. The waveform of the wave loop is unrestricted, including Z-shaped waves, M-shaped waves, V-shaped waves, sine waves, etc. The wave loop includes multiple peaks (also known as proximal apexes), multiple troughs (also known as distal apexes), and wave rods connecting adjacent peaks and troughs. A single peak (proximal or distal) and the two wave rods connected to that peak form a single wave.

[0059] This application provides a coated support 10, as shown in Figures 4-16. The coated support 10 includes a main support 11, a branch support 12, a connecting membrane tube 13, and a first bare wave ring 14. The main support 11 includes a main wave ring 111 and a main coating 112, with the main coating 112 covering the main wave ring 111. The main wave ring 111 is a ring structure formed by connecting multiple waveform units end to end. A waveform unit refers to a single-wave structure composed of wave crests, wave rods, and wave troughs, and the shape of the waveform unit is not limited. Each main wave ring 111 can be a regular ring structure formed by multiple waveform units of equal height, or an irregular ring structure including high and low waves formed by waveform units of different wave heights. Adjacent main wave rings 111 can all be regular ring structures, or all be irregular ring structures including high and low waves, or a combination of two types of ring structures: regular ring structures and irregular ring structures including high and low waves. This is not limited here.

[0060] The main body covering 112 is a tubular structure with openings at both ends. Multiple main body wave coils 111 are arranged axially and connected through the tubular main body covering 112 to form a tubular main body support 11. The distal end of the first bare wave coil 14 is connected to the proximal end of the main body support 11, so that the first bare wave coil 14 is exposed outside the main body covering 112.

[0061] As shown in Figures 5-8, the main support 11 also includes a window 113, which is located on one side of the main support 11, and the lumen of the branch support 12 communicates with the lumen of the main support 11. The branch support 12 includes a circumferential connection 121, which is connected to the window 113. One end of the connecting membrane tube 13 is circumferentially connected to the window 113, and the other end of the connecting membrane tube 13 is circumferentially connected to the circumferential connection 121. The circumferential connection 121 includes a first connection point 121a and a second connection point 121b. The covered support 10 also includes a first axial line 15 and a second axial line parallel to the longitudinal central axis of the main support. The first axial line 15 passes through the first connection point 121a, which is axially closest to the distal end of the covered support 10. The first axial line 15 also intersects the circumferential connection 121 at the second connection point 121b. The second axial line intersects the window 113 at the third connection point 113a and the fourth connection point 113b. The third connection point 113a is located on the distal end side of the fourth connection point 113b. The axial distance between the first connection point 121a and the third connection point 113a is less than the axial distance between the second connection point 121b and the fourth connection point 113b, so that the branch bracket 12 is offset more towards the distal end edge of the window 113 relative to the proximal end edge of the window 113. As shown in Figure 6, the first axial line is parallel to the second axial line and overlaps in the view of the figure. It can be understood that when the circumferential connection 121 and the window 113 are on the same horizontal plane, the first axial line and the second axial line coincide. Specifically, when the connecting line between the first and third connection points is parallel to the longitudinal central axis of the main support, the on-axis distance between the first connection point 121a and the third connection point 113a refers to the distance of the line segment connecting the two points. When the connecting line between the first and third connection points is not parallel to the longitudinal central axis of the main support, the on-axis distance between the first connection point 121a and the third connection point 113a refers to the projection distance of the line segment connecting the two points on the longitudinal central axis of the main support. Similarly, when the connecting line between the second and fourth connection points is parallel to the longitudinal central axis of the main support, the on-axis distance between the second connection point 121b and the fourth connection point 113b refers to the distance of the line segment connecting the two points. When the connecting line between the second and fourth connection points is not parallel to the longitudinal central axis of the main support, the on-axis distance between the second connection point 121b and the fourth connection point 113b refers to the projection distance of the line segment connecting the two points on the longitudinal central axis of the main support.Especially for the covered stent 10 with branch stent 12 at the aortic arch, when the main stent 11 of the covered stent 10 naturally expands and adheres to the inner wall of the blood vessel, the ultra-rigid guidewire 40 extends along the descending aorta into the branch vessel. Due to the angle between the descending aorta and the branch vessel, as well as the curved structure of the aortic arch, during the process of constructing the branch access using the ultra-rigid guidewire 40 at the branch stent 12, or during the implantation of the external small stent using the branch access formed by the ultra-rigid guidewire after the branch access is constructed, it can avoid the angle between the descending aorta and the aortic arch and the branch vessel causing the curved direction of the branch access constructed by the ultra-rigid guidewire 40 to pull the branch stent 12 toward the distal end of the main stent 11. This causes the main stent 11 to be under force, resulting in the already released main stent 11 being moved backward, thus avoiding the overall backward movement of the already released covered stent 10, thereby avoiding the problem of insufficient anchorage at the proximal end of the released main stent 11.

[0062] When the window 113 and the circumferential connection 121 are of regular shape, the window 113 can be circular or elliptical, and the circumferential connection 121 can also be circular or elliptical. In this case, the geometric center of the circumferential connection 121 is closer to the distal end of the main stent 11 than the geometric center of the window 113. This allows the branch stent 12 to be eccentrically positioned relative to the window 113 towards the distal end of the main stent 11 when connected to the window 113 via the connecting membrane tube 13. For a covered stent 10 with a branch stent 12 at the aortic arch, when the main stent 11 of the covered stent 10 naturally expands... After being expanded and attached to the inner wall of the blood vessel, during the implantation of the external small stent using the branch pathway formed by the ultra-rigid guidewire 40 after the branch pathway is constructed, the bending direction of the branch pathway constructed by the ultra-rigid guidewire 40 due to the angle relationship between the descending aorta to the aortic arch and the branch vessels can be avoided. This prevents the branch stent 12 from being pulled towards the distal end of the main stent 11, causing the main stent 11 to be under force and thus causing the already deployed main stent 11 to move backward, preventing the overall backward movement of the already deployed covered stent 10, thereby avoiding the problem of insufficient anchorage at the proximal end of the deployed main stent 11.

[0063] The main support 11 has a tubular structure, wherein the projection of the circumferential connection 121 onto the axial section passing through the axial central axis of the main support 11 lies within the projection of the window 113 onto the axial section passing through the axial central axis of the branch support 12. The branch support 12 includes a first end 122, a middle section 123, and a second end 124. The first end 122 and the second end 124 are oppositely arranged, the middle section 123 is disposed between the first end 122 and the second end 124, and the circumferential connection 121 is located in the middle section 123. The connecting membrane tube 13 is an annular connecting membrane tube 13. One end of the annular connecting membrane tube 13 is circumferentially connected to the window 113 of the main support 11, and the other end of the annular connecting membrane tube 13 is circumferentially connected to the middle section 123 of the branch support 12, thereby connecting the branch support 12 to the main support 11. The other end of the annular connecting membrane tube 13 is circumferentially connected to the middle section 123 of the branch support 12, such that the circumferential connection 121 is located in the middle section 123, rather than at the first end 122 or the second end 124, so that the first end 122 of the branch support 12 is located inside the cavity of the main support 11, and the second end 124 of the branch support 12 is located outside the cavity of the main support 11, as shown in Figures 5-6 and 7.

[0064] The main support 11 also includes an annular support 114, which is disposed along the edge of the window 113 such that the edge of the annular support 114 is approximately equal to the edge of the window 113. The annular support 114 can be made of radiopaque material and is used to support the edge of the window 113 while simultaneously displaying the location of the branch stent 12, so as to facilitate the alignment of the branch stent 12 with the branch vessel orifice. When the window 113 is circular, the annular support 114 is also an annular ring of equal diameter.

[0065] When the circumferential connection 121 and the window 113 are on the same horizontal plane, the width of the connecting membrane tube 13 in any direction is greater than the distance from the circumferential connection 121 to the window 113 in the same direction. This ensures that the connecting membrane tube 13 is not taut when the circumferential connection 121 and the window 113 are on the same horizontal plane. In other words, the connecting membrane tube 13 has sufficient space for the branch stent 12 to float up and down (radially to the main stent 11) along the window 113. Simultaneously, the branch stent 12 can swing 360° circumferentially along its tubular shape, allowing the orientation of the opening at the second end 124 of the branch stent 12, away from the main stent 11, to be adjustable. This makes it easier for the opening at the second end 124 of the branch stent 12 to align with the anatomical shape of the branch vessel opening after the covered stent 10 is implanted into the blood vessel, thus reducing the impact of anatomical complexity on the correspondence between the opening at the second end 124 of the branch stent 12 and the branch vessel opening. The annular connecting membrane tube 13 connects to the middle part of the branch stent 12, so that part of the branch stent 12 is located outside the main stent 11 and part is located inside the main stent 11. It can also make the second end 124 of the branch stent 12 float down to be flush with the main stent 11. Within the range of the annular support 114, the orientation of the opening of the second end 124 of the branch stent 12 is adjustable, which is more convenient to adapt to different anatomical shapes (especially for the anatomical shape of the branch vessel tilted towards the distal end).

[0066] In one embodiment, as shown in FIG6, the window 113 is circular, and the circumferential connection 121 is also circular. The diameter of the circumferential connection 121 is smaller than the diameter of the window 113. The center of the circumferential connection 121 does not overlap with the center of the window 113, and the center of the circumferential connection 121 is closer to the distal end of the main support 11 than the center of the window 113. This results in the branch support 12 being eccentrically positioned relative to the window 113 toward the distal end of the main support 11 when it is connected to the window 113 via the connecting membrane tube 13. Specifically, the projection of the circumferential connection 121 onto the axial section passing through the axial central axis of the branch bracket 12 is completely within the projection of the window 113 onto the axial section passing through the axial central axis of the branch bracket 12. This means that the diameter of the circle of the window 113 is larger than the diameter of the circumferential connection 121, and the projection of the circumferential connection 121 onto the axial section passing through the axial central axis of the branch bracket is internally tangent to the projection of the window 113 onto the axial section passing through the axial central axis of the branch bracket 12, or the projection of the circumferential connection 121 onto the axial section passing through the axial central axis of the branch bracket 12 is completely within the projection of the window 113 onto the axial section passing through the axial central axis of the branch bracket 12.

[0067] The main support 11 and the branch support 12 can be connected to the axial middle portion of the branch support 12, that is, the circumferential connection 121 can be set at the axial middle portion of the branch support 12. The specific connection position of the circumferential connection 121 can be selected from any one of the circumferential outer surfaces within the middle one-third of the axial length range when the branch support 12 is divided into three equal parts along its axial direction. In one embodiment, the window 113 of the main support 11 and the branch support 12 are circumferentially connected to the axial middle portion of the branch support 12 by an annular connecting membrane cylinder 13. The width of the annular connecting membrane cylinder 13 in any radial direction is greater than the difference between the diameter of the window 113 and the circumferential connection 121. When the branch support 12 is set as a tubular support of equal diameter... When the stent is in place, the width of the annular connecting membrane tube 13 in any radial direction is greater than the difference between the diameter of the window 113 and the outer diameter of the branch stent 12. This allows the annular connecting membrane tube 13 to allow the branch stent 12 to float vertically (in the radial direction of the main stent 11). At the same time, the branch stent 12 can swing 360° around its tubular circumference, making the orientation of the opening of the second end 124 of the branch stent 12 away from the main stent 11 adjustable. This makes it easier for the opening of the second end 124 of the branch stent 12 to align with the branch vessel opening when using a guidewire to approach the branch vessel after the covered stent 10 is implanted into the blood vessel, thus reducing the influence of the complexity of the anatomical morphology on the correspondence between the opening of the second end 124 of the branch stent 12 and the branch vessel opening.

[0068] The covered stent 10 also includes a wrapping member 16, which can be configured as a membrane 16a or a beam diameter line. The wrapping member 16 cooperates with the beam diameter detachable member 24 to form a semi-binding structure. The radial constriction and release of the covered stent 10 are achieved through the cooperation of the wrapping member 16 and the beam diameter detachable member 24. In one embodiment, the wrapping member 16 is configured as a membrane 16a, which is connected to one side of the main stent 11. The membrane 16a releasably wraps the main stent 11 so that the main stent 11 is radially compressed or released, thereby constraining the compressed main stent 11 within the membrane 16a or allowing the main stent 11 to expand naturally after being unwrapped.

[0069] Referring to Figures 9-10, the main coating 112 includes a first film layer 1121 and a linear film 1122. The linear film 1122 is wound around the circumference of the main coating 112. The linear film 1122 can be multiple lines wound around the coating support 10 in a direction parallel to the radial direction, or it can be one or more lines wound spirally around the coating support 10 in a direction. The first film layer 1121 is attached to one side of the main waveguide 111. The linear film 1122 can be disposed between the first film layer 1121 and the main waveguide 111, or it can be disposed on the side of the first film layer 1121 away from the main waveguide 111, or it can be disposed on the side of the main waveguide 111 away from the first film layer 1121, which is not limited here. In one embodiment, the linear film 1122 is disposed on the side of the main waveguide 111 away from the first film layer 1121, and it can cooperate with the first film layer 1121 to constrain the main waveguide 111.

[0070] In one embodiment, the main body coating 112 further includes a second film layer 1123, which is attached to the side of the main body waveguide 111 away from the first film layer 1121. The first film layer 1121 is attached to the inner side of the main body waveguide 111, and the second film layer 1123 is attached to the outer side of the main body waveguide 111. A linear film 1122 is disposed between the main body waveguide 111 and the second film layer 1123, and the linear film 1122 is spirally wound upward along the circumferential direction of the coating support 10. The linear film 1122 and the first film layer 1121, the first film layer 1121 and the second film layer 1123, and the linear film 1122 and the second film layer 1123 can all be fixed together by gluing or hot pressing.

[0071] The linear membrane 1122 can be a linear structure formed by a single strand or multiple strands of wire, with an average wire diameter ranging from 0.05 mm to 0.3 mm. The cross-sectional area of ​​the linear structure can be circular, elliptical, rectangular, etc., and the thickness of the linear structure can be uniform or non-uniform in its extension direction, which is not limited here. When the cross-sectional area of ​​the linear structure is non-circular, the thickness of the linear structure in the radial direction of the membrane support 10 ranges from 0.05 mm to 0.3 mm. The linear membrane 1122 can be made of biocompatible polymer materials such as PTFE wire. In one embodiment, the linear membrane 1122 is spirally wound around the membrane support 10 in the circumferential direction, and the spiral angle ranges from 0° to 45°. For example, when the linear membrane 1122 is spirally wound around the membrane support 10 in the circumferential direction, the spiral angle can be 0°, 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, etc. The linear membrane 1122 can be a single strand spirally rising at equal intervals or a non-equal interval spiral rising; the linear membrane 1122 can also be multiple strands spirally spaced at equal intervals or non-equal intervals. There are no limitations here, as long as the linear membrane 1122 passes around each wave loop.

[0072] The main support 11 includes opposing first sides 11a and second sides 11b along the circumferential direction, defining each side 11a and 11b as an arc occupying 180° in the circumferential direction. As shown in Figure 4, a membrane 16a is connected to the first side 11a of the main support 11. The membrane 16a is connected to the main support 11 by a binding wire 17. In one embodiment, the portion of the membrane 16a near the proximal end is connected to the main support 11 near the proximal end by a connector. In this embodiment, the axial length of the membrane 16a is equal to the axial length of the main membrane 112. In other embodiments, the axial length of the membrane 16a may also be approximately equal to the axial length of the main membrane 112. Here, "approximately equal to" means that the axial length of the membrane 16a is equal to the axial length of the main membrane 112. The axial length difference ratio is less than or equal to 10%, such that the proximal end of the membrane 16a extends at least to the center of the main body wavelet 111 closest to the heart, and the distal end of the membrane 16a extends at least to the axial center of the main body wavelet 111 furthest from the heart, and neither end of the membrane 16a exceeds the ends of the main body support 11. The larger of the axial lengths of the membrane 16a and the main body covering 112 is defined as H1, and the smaller of the axial lengths of the membrane 16a and the main body covering 112 is defined as H2. The axial length difference ratio is then (H1-H2) / H2. In one embodiment, the membrane 16a is rectangular, the main body covering 112 is tubular, and the axial length of the membrane 16a is slightly larger than the axial length of the main body covering 112. Therefore, the axial length of the membrane 16a is H1, and the axial length of the main body covering 112 is H2, as shown in Figures 11-12. The width of the membrane 16a (the direction of which is perpendicular to the axis of the covered support 10) is defined as W. The perimeter of the covered support 10 at a position corresponding to the width of the membrane 16a in its natural expansion state is defined as C. The relationship between W and C is: W≤C / 4. This is so that when the membrane 16a wraps and constrains the radially compressed covered support 10, the radial space in which the adjustable bendable conduit 28 can move is not too large when it moves axially within the compressed covered support 10.Setting W≤C / 4 allows for a smaller compression radius in the semi-bound state of the covered stent 10, meaning the radial compression degree of the covered stent 10 remains relatively large. On one hand, this ensures the channel size is slightly larger than the outer diameter of the adjustable bend conduit 28, facilitating smooth delivery of the adjustable bend conduit 28. Even if the radially compressed covered stent 10 has a crowded wavelet stack, the pre-placed conduit within the covered stent 10, due to the soft wrapping of the membrane 16a, provides radial soft buffering, reducing friction between the pre-placed conduit and the stacked main wavelets 111, ensuring smooth delivery even when axial delivery is required. On the other hand, it ensures the channel size is not... If the diameter is too large, it will limit the radial space of the adjustable bendable catheter 28, which can prevent the adjustable bendable catheter 28 from bending in the channel during delivery. In addition, the radial compression of the covered stent 10 by the sheath 16a is less than the compression of the covered stent 10 by the sheath 23, resulting in less friction on the adjustable bendable catheter 28. Furthermore, since the wrapping of the main stent 11 by the sheath 16a is uniform in the axial direction of the main stent 11, it can also avoid the situation where, when the covered stent 10 is bundled with wire, some unbound parts of the main corrugated coil 111 will bend due to the self-expansion force, resulting in a larger channel and the adjustable bendable catheter 28 bending in the larger channel space.

[0073] It is understandable that, in order to make the radial compression of the membrane 16a greater, the relationship between the width W of the membrane 16a and the lumen circumference C of the covered stent 10 at the corresponding position can be set to satisfy: W≤C / 5; even if the channel space of the covered stent 10 after radial compression is small after the membrane 16a wraps the covered stent 10, since the membrane 16a is a flexible membrane, its radial compression of the covered stent 10 is a soft wrapping. When the pre-placed catheter is pre-placed in this space along the axial direction, the pre-placed catheter can also slide smoothly along the axial direction along the narrow space. At the same time, the membrane 16a radially squeezes the covered stent 10, which can prevent the pre-placed catheter from bending in the channel space.

[0074] The membrane 16a has an elongated strip structure. In one embodiment, the membrane 16a has a rectangular sheet structure, with its length direction corresponding to the axial direction of the main support 11. At least one limiting perforation 164 is provided near the edge of each of the two long sides of the membrane 16a. When multiple main wave coils 111 are provided axially, multiple limiting perforations 164 are provided at intervals along the axial direction near the edge of each of the two long sides of the membrane 16a, so that the guide wire 241 can pass through the limiting perforations 164 on the two long sides of the membrane 16a in sequence, so that the membrane 16a can be formed into a tubular body, thereby wrapping the radially compressed membrane support 10. In this embodiment, a limiting member 165 is provided between the limiting perforation 164 and the edge of the membrane 16a to prevent the membrane hole from expanding to the edge of the membrane 16a and breaking the closed state of the membrane hole, thereby avoiding the reliability of the guide wire 241 passing through the membrane hole and forming a tubular body around the membrane 16a.

[0075] As shown in Figure 4 and Figures 9-16, the membrane 16a is connected to the first side 11a of the main body support 11 by a binding wire 17. The binding wire passes directly through the main body covering 112 and the membrane 16a and is then tied. The membrane 16a also includes a buffer 163, which is disposed in the middle region of the membrane 16a and extends along the plane of the membrane 16a. In one embodiment, the buffer 163 may be configured as a reinforcing line extending axially, with the binding wire passing through the membrane 16a and crossing the buffer 163; in other embodiments, the buffer 163 may also be configured as a reinforcing line extending laterally or obliquely. The buffer 163 may be formed in the plane of the membrane 16a or on the surface of the membrane 16a by heat treatment together with the membrane 16a. When the film support 10 is loaded or released, the buffer 163 can limit the relative movement between the film 16a and the main film 112 caused by friction, thereby reducing the force on the film 16a being pulled by the binding wire, thus reducing the possibility of the film 16a causing the binding wire to pass through the film pores on the main film 112 and the film pores on the film 16a to enlarge.

[0076] The 16a sheath can be made of PTFE or PET film, and the reinforcing suture can be made of biocompatible polymers such as PTFE. PTFE sutures or films have good thermal properties, are chemically inert, self-lubricating, and non-stick. They are not easily wetted by tissue fluid, are corrosion-resistant, have the best aging life among plastics, are non-toxic, can withstand pressure, can be implanted in the human body, and can withstand certain tension and tensile forces.

[0077] The main support 11 includes a binding attachment 115, which extends along the main film 112. The main film 112 includes a first perforation 1124 and a second perforation 1125, which pass through the inner and outer sides of the main film 112 respectively. The first perforation 1124 and the second perforation 1125 are respectively located on both sides of the extension direction of the binding attachment 115. The binding attachment 115 can be configured as a wave rod of a main wave coil 111, or it can be a binding wire set on the main film 112. The binding wire can be fixed to the main film 112 by gluing or hot pressing. In one embodiment, the binding attachment 115 is disposed at the proximal end of the main support 11. The main support 11 includes a main wave ring 111 disposed at the proximal end. The binding wire 17 is connected to the wave rod, wave crest, or wave trough of the main wave ring 111. That is, the binding attachment 115 is set as the wave rod, wave crest, or wave trough of the main wave ring 111. The main wave ring 111 is formed by a metal wire rod extending in a wave-like manner along the circumference of the main support 11 to form a wave-shaped ring with the ends connected. The first through hole 1124 and the second through hole 1125 are respectively disposed on both sides of the extension direction of the binding attachment 115.

[0078] The film 16a includes a third perforation 161 and a fourth perforation 162, which are respectively located on both sides of the buffer 163 extending in the direction of extension. The binding thread 17 passes through the first perforation 1124 and the second perforation 1125 and crosses the binding attachment 115 before being knotted. It then passes through the third perforation 161 and the fourth perforation 162 and crosses the buffer 163 before being knotted again. This allows the binding thread to cross the binding attachment 115 when passing through the main film 112, and the binding thread mainly pulls on the binding attachment 115. When the binding thread is under stress, the possibility of the membrane holes in the first perforation 1124 and the second perforation 1125 enlarging can be reduced. The buffer 163 is provided so that when the binding thread is under stress, the buffer 163 is mainly pulled. When the binding thread is under stress, the possibility of the membrane holes (at the third perforation 161 and the fourth perforation 162) on the film 16a enlarging can be reduced.

[0079] One or more fixing points can be provided between the membrane 16a and the main support 11. The fixing points are connected to the corresponding binding attachments 115. In one embodiment, one fixing point is provided between the membrane 16a and the main support 11. The binding thread 17 includes a first binding thread 171. The first binding thread 171 passes through the first perforation 1124 and the second perforation 1125 on the main membrane 112 and crosses a binding attachment 115. The two ends of the first binding thread 171 are located outside the main support 11. At this time, the first binding thread 171 can tie one or two knots on the outside of the main support 11. The knot is finally formed between the membrane 16a and the main support 11. Then the first binding thread 171 passes through the third perforation 161 and the fourth perforation 162 of the membrane 16a and is knotted on the side of the membrane 16a away from the main support 11 to prevent the binding thread from loosening. At the same time, the knot of the binding thread is formed outside the lumen of the membrane support 10 to avoid affecting the blood flow in the lumen. In other embodiments, as shown in FIG12, two fixing points may be provided between the film 16a and the main support 11. The binding wire 17 also includes a second binding wire 172. The second binding wire 172 can be fixedly connected to the perforations on the film 16a and the film support 10 in the same way as the first binding wire 171, which will not be described in detail here.

[0080] In one embodiment, as shown in Figures 9-10, the binding wire 17 is connected to the wave rod of the main wave coil 111. At least one linear membrane 1122 is provided on the proximal and distal ends of the binding wire 17 to limit the expansion of the first perforation 1124 and the second perforation 1125 toward the proximal and distal ends, respectively. The shortest distance L1 of the linear membrane 1122 in the axial direction to the edge of the first perforation 1124 satisfies: L1≤3mm, and the shortest distance L2 of the linear membrane 1122 in the axial direction to the edge of the second perforation 1125 satisfies: L2≤3mm. In other embodiments, the binding thread can be connected to the crest of the main wave loop 111, and at least one linear membrane 1122 is provided on the distal end of the binding thread 17 to limit the enlargement of the perforation through the main covering film 112 on the inner side of the crest bend; the binding thread can also be connected to the trough of the main wave loop 111, and at least one linear membrane 1122 is provided on the proximal end of the binding thread 17 to limit the enlargement of the perforation through the main covering film 112 on the inner side of the trough bend. In other embodiments, the steel sleeve wraps around both ends of the main wave loop 111 to make the main wave loop 111 a closed wave-shaped ring, and the binding thread can also be connected to the main wave loop 111, with the binding thread close to the edge of the steel sleeve, thereby using the steel sleeve to limit the movement of the binding thread relative to the main covering film 112.

[0081] As shown in Figures 4-6 and 16, the main wave loop 111 is formed by connecting multiple single waves sequentially. The main support 11 includes a main wave loop 111 disposed at the proximal end of the covered support 10. The main wave loop 111 includes a first wave crest 1111, a first wave trough 1112, and a first wave rod 1113 connecting the first wave crest 1111 and the first wave trough 1112. The first wave rod 1113 is used as a binding attachment 115. The first perforation 1124 and the second perforation 1125 are respectively disposed on both sides of the extension direction of the first wave rod 1113. The line connecting the geometric center of the first perforation 1124 and the geometric center of the second perforation 1125 is defined as W. 1. Define the intersection point of W1 and the first wave rod 1113 as Q, and define the tangent line passing through point Q and tangent to the wave rod as W2. The included angle α between W1 and W2 satisfies: 60°≤α≤90° (the included angle between the two lines is in the range of 0°~90°). When the vertical distances between the first perforation 1124 and the second perforation 1125 and the first wave rod 1113 are both constant, if the included angle between W1 and W2 is too small, the line segment connecting the first perforation 1124 and the second perforation 1125 will be too long. When the first binding wire 171 is subjected to tensile force, it will be difficult to apply the main tensile force to the wave rod of the main wave ring 111, reducing the force on the edge of the membrane hole, which may lead to the enlargement of the membrane hole.

[0082] This application also provides a stent system 100, as shown in Figures 17-37. The stent system 100 includes a delivery device 20 and the aforementioned covered stent 10. The delivery device 20 includes a semi-binding structure that releasably binds the main stent 11 so that the main stent 11 is radially compressed or released. The stent system 100 also includes an adjustable bend conduit 28 that extends along the lumen of the main stent 11. The distal end of the adjustable bend conduit 28 enters from the distal end of the main stent 11 and exits from the branch stent 12.

[0083] The conveying device 20 includes a sheath core assembly 21, a support rod 22, a sheath tube 23, a detachable diameter member 24, and a handle assembly 25. The sheath core assembly 21 includes an inner sheath core 211 and an outer sheath core 212. The inner sheath core 211, outer sheath core 212, support rod 22, and sheath tube 23 are sequentially sleeved from the inside to the outside, and each pair of the inner sheath core 211, outer sheath core 212, and sheath tube 23 can move relative to each other axially. The support rod 22 is sleeved on the outside of the sheath core assembly 21. The conveying device 20 also includes a guide head 26, which is located at the distal end of the inner sheath core 211. The distal end of the support rod 22 and the proximal end of the guide head 26 are spaced apart to form a loading space for the film-coated support 10, as shown in Figure 17. For ease of showing the internal structure of the sheath tube 23, this figure shows the internal components of the sheath tube 23.

[0084] As shown in Figure 18, the support rod 22 includes a first channel 221, a second channel 222 and a third channel 223 that run through the axis. The first channel 221 allows the sheath core assembly 21 to pass through the axis, the second channel 222 allows the bundle diameter guide wire 241 to pass through the axis, and the third channel 223 allows the adjustable bendable guide tube 28 to pass through the axis.

[0085] As shown in Figure 19, the detachable bundle diameter member 24 may include a bundle diameter guide wire 241. The distal end of the detachable bundle diameter member 24 is sewn along the limiting perforations 164 on the two long edges of the membrane 16a so that the membrane 16a can be closed or opened to release the support. The proximal end of the detachable bundle diameter member 24 is connected to a safety buckle 242, which is detachably fixed to the handle assembly 25 to prevent the membrane support 10 from being accidentally released.

[0086] As shown in Figure 19, the guide wire 241 is used to pass through the holes near the edges of the two long sides of the membrane 16a in a staggered manner along the axial direction, thereby wrapping the covered stent 10 inside the membrane 16a and radially compressing the covered stent 10 within the membrane 16a, so that the covered stent 10 is in a radially compressed bundled state. The distal end of the guide wire 241 is used to pass through the limiting perforations 164 provided at the edges of the two long sides of the membrane 16a in a staggered manner along the axial direction, so as to enclose the membrane 16a into a tubular body, thereby radially compressing and constricting the covered stent 10 within the membrane 16a. By retracting the guide wire 241, the restriction of the guide wire 241 on the limiting perforations 164 can be released, thereby releasing the covered stent 10 from the compressed state and relieving the binding of the membrane 16a on the covered stent 10. The proximal end of the guide wire 241 is connected to a pull ring buckle as a safety buckle 242. The pull ring buckle is detachably fixed to the handle assembly 25. When it is necessary to release the covered support 10, first release the safety buckle 242 from the handle assembly 25, and then pull the safety buckle 242 back to open the film 16a, release the radial restraint on the covered support 10, and allow the covered support 10 to expand naturally.

[0087] In other embodiments, the releasable member 24 may also include a releasable suture structure that passes through holes near the edges of the two long sides of the membrane 16a along the axial direction to radially compress the covered support 10 within the membrane 16a. The releasable member 24 is not limited here, as long as it can cooperate with the membrane 16a to achieve radial contraction and release of the covered support 10.

[0088] As shown in Figures 20-28, the adjustable bend conduit 28 includes an adjustable bend 281 and an adjusting member 282. The adjustable bend 281 includes an extension section 2811 and an adjustable bend section 2812. The adjustable bend section 2812 is located on the distal end side of the extension section 2811. When a limiting hole is provided, the adjustable bend section can refer to the portion of the adjustable bend from the position corresponding to the distal end face of the limiting hole to the position where the distal end of the adjustable bend connects with the distal end of the adjusting member. The axial length of the adjustable bend section when it is not bent can be set within the range of 0.5cm to 10cm. The adjustable bend conduit 28 also includes a limiting hole 283, which is located on the proximal end side of the adjustable bend section 2812. The limiting hole can be located on the wall of the adjustable bend or outside the wall of the adjustable bend. The adjusting member 282 includes a distal end 2821 and an adjusting section 2822. The distal end 2821 of the adjusting member 282 is connected to the distal end of the adjustable bend 281. The adjusting member 282 passes through the limiting hole 283 and extends towards the proximal end, thereby forming the adjusting section 2822 between the limiting hole 283 and the distal end 2821. This allows the adjusting member 282 to bend the distal end of the adjustable bend 281 when the adjusting member 282 is pulled back, thus achieving the bending of the adjustable section 2822. It is understood that the adjusting member 282 can be configured as a pull cable extending axially. The adjusting member 282 extends towards the proximal end to the operating handle and extends beyond the operating handle. A bending button can be provided at the proximal end of the adjusting member 282, allowing the adjusting member 282 to be pulled back via the bending button, causing the adjusting member 282 to move axially relative to the adjustable bend 281, thereby bending the adjusting section 2822.

[0089] The semi-binding structure includes a wrapping element 16 and a diameter-detachable element 24. The diameter-detachable element 24 cooperates with the wrapping element 16 to achieve radial constriction and release of the covered stent 10. Since the stent system 100 is in its loaded state, the distal end of the adjustable bend conduit 28 extends beyond the second end 124 of the branch stent 12 and passes through the gap enclosed by the wrapping element 16a. The diameter-detachable element 24 is positioned to pass through the gap between the adjusting section 2822 and the adjustable bend section 2812, and is located at the distal end 2821 of the adjusting element 282. Between the limiting hole 283 and the cross formed by the connection between the distal end 2821 of the adjusting member 282 and the distal end of the adjustable bend 281, the diameter release member 24 has a limiting effect on the cross, which makes it easy for the distal end of the adjustable bend duct 28 to extend out of the sheath 16a and to always keep part of the adjustable bend duct 28. The distal end 2821 of the adjustable bend duct 28 will not be brought into the sheath 16a due to the friction of the sheath 23 retracting, which is not conducive to the subsequent extension of the adjustable bend duct 28 out of the sheath 16a.

[0090] In one embodiment, the wrapping member 16 is configured as a membrane 16a, and the diameter-detachable member 24 is configured as a diameter guide wire 241. The diameter guide wire 241 is used to pass through the holes near the edges of the two long sides of the membrane 16a in an axially staggered manner to enclose the membrane 16a into a tubular body, thereby wrapping the covered support 10 inside the membrane 16a and radially compressing the covered support 10 inside the membrane 16a, so that the covered support 10 is in a radially compressed diameter state. During the release process of the main support 11, the diameter guide wire 241 can be retracted to release the restriction of the diameter guide wire 241 on the limiting perforation 164, thereby releasing the covered support 10 from the compressed state and releasing the membrane 16a from the binding of the covered support 10.

[0091] Furthermore, the adjustable bend 281 includes a first lumen 28a, and the limiting hole portion 283 includes a lumen structure extending axially. The distal end of the limiting hole portion extends to the proximal side of the adjustable bend section 2812. In one embodiment, the lumen structure is configured as a second lumen 283a, and the distal end of the second lumen 283a extends to the proximal side of the adjustable bend section 2812, thus the adjustable bend catheter 28 forms a double lumen. The first lumen 28a and the limiting hole portion can be configured not to communicate, so as to avoid affecting the independence and inner wall smoothness of the first lumen 28a when the adjusting member 282 extends along the second lumen 283a. This ensures that after the adjustable bend section 2812 of the adjustable bend catheter 281 is bent, the (ultra-fine or ultra-rigid) guidewire along the first lumen 28a of the adjustable bend catheter 28 can be inserted into the branch blood vessel without obstruction.

[0092] Taking the limiting hole 283 as an example of a second cavity 283a extending axially, it can be understood that when the adjusting member 282 of the adjustable bend conduit 28 does not bend the adjustable bend section 2812, both the adjustable bend conduit 281 and the adjusting member 282 are in a straight state, and the adjusting section 2822 of the adjusting member 282 is attached to the outer wall of the adjustable bend section 2812, as shown in Figure 22 and Figure 24. When the adjusting member 282 is pulled backward on this basis, part of the adjusting section 2822 enters the second cavity 283a from the distal end of the second cavity 283a. The distal end of the adjustable bend section 2812 is bent towards the side connected to the adjusting member 282, so that the part of the adjusting section 2822 exposed outside the second cavity 283a deviates from the arc formed by the adjustable bend section 2812, as shown in Figure 23. The adjustable bendable catheter 28 can be configured to bend the adjustable bend segment 2812 of the adjustable bendable catheter 28 and align it with the branch vessel opening after the main stent 11 is released. Alternatively, the adjustable bend segment 2812 can be directly inserted into the branch vessel, or the ultra-fine guide wire 30 can be directly inserted into the branch vessel using the adjustable bendable catheter 28 as a guide. No limitation is made here.

[0093] Furthermore, the second cavity 283a can be disposed on the wall of the adjustable bend 281, extending axially along the wall of the adjustable bend 281 to form a cavity-shaped hole. The wall of the adjustable bend 281 can include a braided layer 2813 and a polymer layer 2814 from the inside to the outside. The second cavity 283a is disposed on the polymer layer 2814. Generally, the thickness of the polymer layer 2814 is increased so that its thickness slightly exceeds the size of the second cavity 283a. The second cavity 283a can be formed in the polymer layer 2814, as shown in Figures 20-21. In other embodiments, as shown in Figures 24-26, the second lumen 283a is located outside the adjustable bend 281. The wall of the adjustable bend 281 may include a braided layer 2813 and a polymer layer 2814 from the inside to the outside. The adjustable bend conduit also includes an arc-shaped wall 2815, which extends axially and is located outside the polymer layer 2814. The second lumen 283a is formed axially between the arc-shaped wall 2815 and the outer wall of the polymer layer. The distal end of the arc-shaped wall 2815 extends to the proximal end of the adjustable bend section 2812. By placing the second lumen 283a outside the adjustable bend 281, the overall outer diameter of the adjustable bend conduit 28 is reduced. In particular, the thickness of the polymer layer 2814 can greatly improve the overall flexibility of the adjustable bend conduit 28. In other embodiments, as shown in FIG27, the limiting hole portion 283 includes a limiting ring disposed on the outside of the adjustable bend 281 and located on the proximal side of the adjustable bend section 2812, so as to facilitate the connection of the distal end portion 2821 of the adjusting member 282 to the distal end of the adjustable bend 281. The adjusting member 282 passes through the limiting ring and extends toward the proximal end, thereby forming its adjusting section 2822 between the limiting ring and the distal end portion 2821.

[0094] In one embodiment, the stent system 100 can bend the adjustable bend 2812 and then directly insert the bent adjustable tube 281 into the branch vessel orifice. Then, the ultra-rigid guidewire 40 is inserted into the branch vessel along the adjustable bend 281, and then the adjustable catheter 28 is withdrawn. Thus, the ultra-rigid guidewire 40 inserted into the branch vessel is used as a delivery pathway for external small branches. This stent system 100 can directly insert the adjustable bend 281 into the branch vessel without the need for the insertion process of the ultra-fine guidewire 30, which can optimize the surgical procedure and reduce the operation time.

[0095] In other embodiments, the stent system 100 also includes an ultra-fine guidewire 30. After the adjustable bend 2812 of the adjustable bend catheter 281 is bent, it can be used to guide the ultra-fine guidewire 30, thereby facilitating its insertion into the branch vessel. After the ultra-fine guidewire 30 has entered the branch vessel to a certain length (ensuring that the ultra-fine guidewire 30 is not pulled out of the branch vessel after the adjustable bend catheter 28 is unbent), the bending of the adjustable bend 2812 can be cancelled (avoiding the adjustment segment from becoming taut), so that the adjustment segment 2822 is attached to the outer wall of the adjustable bend 2812, rather than being far from it, or the adjustment segment is in a non-taut state. Pushing forward the adjustable bend catheter 28 allows it to follow the ultra-fine guidewire 30 into the branch vessel. After the adjustable bend catheter 281 is inserted into the branch vessel, the ultra-fine guidewire 30 is withdrawn, and then an ultra-rigid... The guidewire 40 is inserted into the branch vessel along the adjustable bend 281, thereby using the ultra-rigid guidewire 40 inserted into the branch vessel as a delivery pathway for the external small branch. In this stent system 100, during the process of the adjustable bend catheter 28 entering the branch vessel, the ultra-fine guidewire 30 is first selected into the branch vessel by the guiding effect of the adjustable bend segment 2812. Then, the ultra-fine guidewire 30 already inserted into the branch vessel guides the adjustable bend catheter 28. Thus, during the process of the adjustable bend catheter 28 entering the branch vessel, the guiding effect of the ultra-fine guidewire 30 can be relied upon, without the need for the adjustable bend segment 2812 to remain bent. That is, during the process of the adjustable bend catheter 28 entering the branch vessel, the adjusting segment 2822 can be kept attached to the outer wall of the adjustable bend segment 2812, rather than away from the adjustable bend segment 2812, thereby avoiding the possibility of damage to the vessel by the adjusting segment 2822.

[0096] The adjustable bending guide tube 28 also includes a limiting buckle 284, which is disposed on the distal side of the limiting hole portion 283 and close to the limiting hole portion 283, so that a limiting hole 285 is formed between the adjustable bending section 2812 and the adjusting member 282 between the limiting buckle 284 and the distal end 2821 of the limiting hole portion 283. The diameter release member 24 can pass through the limiting hole 285. Combined with the limiting effect of the diameter release member 24, the possibility of the adjustable bending guide tube 28 retracting axially can be further reduced, so that the entire adjustable bending section 2812 is kept outside the membrane 16a, which facilitates the subsequent adjustment of the bending state.

[0097] As shown in Figure 17, the handle assembly 25 includes a fixed handle 251, a sliding handle 252, and a wing 253. The proximal end of the fixed handle 251 includes a guide rail 2511 extending proximally. The proximal end of the sheath 23 is connected to the sliding handle 252. The sliding handle 252 is positioned around the guide rail 2511 on one side of the proximal end of the fixed handle 251, allowing the sliding handle 252 to slide along the guide rail 2511, which can retract the sheath 23 to release the lumen support from the distal end of the sheath 23. The wing 253 is located on the proximal side of the catheter and has a channel communicating with a channel in the support rod 22 for the adjustable bend catheter to pass through, facilitating operation of the adjustable bend catheter.

[0098] As shown in Figures 29-31, the conveyor also includes a rear-release structure for hooking the first bare wave coil 14, thereby realizing the rear release of the first bare wave coil 14 at the proximal end of the covered stent 10. The conveyor includes a locking member 27 connected to the distal end of the outer sheath core 212; the locking member 27 includes multiple claws 271 and a connecting part 272, and the proximal end of the guide head 26 is provided with a locking part 261 and a locking groove 262; the multiple claws 271 radiate and disperse from the connecting part 272 toward the distal end, and the connecting part 272 fixes the multiple claws 271 to the distal end of the outer sheath core 212, wherein the multiple claws 271 can respectively engage with the locking groove 262. 62. A locking part 261 is disposed on the distal end of the locking groove 262. The locking part 261 includes a locking surface 2611 and a locking step 2612. The inner circumferential surface of the sheath 23 is fitted onto the locking surface 2611, and the distal end face of the sheath 23 abuts against the locking step 2612, so that the guide head 26 can be fitted and embedded into the distal end of the sheath 23, while the locking claw 271 and the locking groove 262 are retracted into the sheath 23. It can be understood that the cooperation between the locking piece 27 and the locking groove 262 forms the above-mentioned detachable post-release structure, that is, the post-release structure includes a closable state formed by the locking piece 27 and the locking groove 262 engaging, and an open state formed by the locking piece 27 and the locking groove 262 moving away from each other. When in the closable state, the post-release structure can temporarily fix the first bare wave coil 14 at the proximal end of the covered stent 10 before post-release.

[0099] Taking the stent system 100 provided in this application for the aortic arch and the branch stent 12 corresponding to the left subclavian artery 50 (a branch vessel) as an example (especially for the anatomical shape where the branch vessel extends from the branch vessel opening in a direction away from the heart and has a large angle with the ascending aorta), the surgical procedure for implantation of the stent system 100 provided in this application in the aortic arch is briefly summarized as follows:

[0100] First, the ultra-rigid guidewire 40 is delivered to the ascending aorta to establish the main access. The stent system 100 is then delivered along the ultra-rigid guidewire 40 to the aortic arch, so that the distal end of the stent system 100 is close to the left subclavian artery. The sheath 23 is then withdrawn to the distal end of the covered stent 10, exposing the capsule 16a and the covered stent 10, which is wrapped by the capsule 16a and is in a semi-restrained state, as shown in Figure 32.

[0101] As shown in Figure 33, by pulling the adjustment button and adjusting component 282, the adjustable section 2812 is adjusted so that its extension direction is in line with the extension direction of the left subclavian artery, and the distal end of the adjustment catheter is oriented directly towards the opening of the left subclavian artery. Based on this, it is easy and time-saving to directly push the adjustable catheter 28 into the left subclavian artery or to deliver the ultra-fine guidewire 30 along the adjusted adjustable catheter 28 into the left subclavian artery.

[0102] Taking the adjustable bend segment 2812 of the adjustable bendable catheter 28 as an example, after bends, it guides the ultra-fine guidewire 30. As shown in Figure 34, the ultra-fine guidewire 30 is inserted into the left subclavian artery. After the ultra-fine guidewire 30 has entered the left subclavian artery to a certain length, the bend of the adjustable bend segment 2812 is canceled. Then, the adjustable bendable catheter 28 is pushed forward to align with the ultra-fine guidewire 30 as it enters the left subclavian artery. The ultra-fine guidewire 30 is then withdrawn, and another ultra-stiff guidewire 41 is delivered along the adjustable bendable catheter 28 to the left subclavian artery 50, thus completing the construction of the external branch. The access can be established by directly pushing the adjustable bend catheter 28 into the branch vessel orifice, selecting the adjustable bend catheter 28 into the branch vessel, and then delivering another ultra-rigid guidewire along the adjustable bend catheter 28 to the left subclavian artery, thereby completing the access for the external branch. The position of the stent system 100 is then finely adjusted so that the annular support 114 is aligned with the left subclavian artery orifice. The bundle diameter guidewire 241 is then withdrawn to release the semi-restrained state of the covered stent 10, allowing the main stent 11 to naturally expand and adhere to the inner wall of the aortic arch, as shown in Figures 35-36.

[0103] Then, the adjustable bendable catheter 28 is withdrawn, followed by the outer sheath core 212. The release structure is then removed, and the delivery device 20 of the covered stent 10 is further withdrawn, as shown in Figure 37. An external branch is then implanted along the pathway established by another ultra-rigid guidewire 41. One end of the external branch overlaps and is anchored with the branch stent 12, while the other end rests against the branch vessel wall. Because the branch stent 12 is eccentrically positioned relative to the window 113 towards the distal end of the main stent 11, during the implantation of the external branch, the branch stent 12 will not be pulled by the other ultra-rigid guidewire 40 towards the distal end of the main stent 11, thus preventing damage to the main stent. The force applied to the stent 11 causes the deployed main stent 11 to move backward, preventing the deployed covered stent 10 from moving backward as a whole. This avoids the problem of insufficient anchorage at the proximal end of the deployed main stent 11. In addition, due to the angle between the branch vessel and the aortic arch, the branch stent 12 deflects towards the proximal end during the process of conforming to the guidewire. Combined with the eccentric setting of the branch stent 12 relative to the window 113 towards the distal end of the main stent 11, the port of the second end 124 of the branch stent 12 can be more aligned with the center of the branch vessel opening when it is not eccentrically set, which is beneficial for the subsequent implantation of external branches.

[0104] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above 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.

[0105] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A covered stent, characterized in that, The covered support includes a main support, branch supports, and connecting membrane tubes. The main support includes a window located on one side of the main support. The branch supports are connected to the window, and the lumen of the branch supports communicates with the lumen of the main support through the window. The branch supports include a circumferential connection. One end of the connecting membrane tube is circumferentially connected to the window, and the other end of the connecting membrane tube is circumferentially connected to the circumferential connection. The circumferential connection includes a first connection point, which is axially closest to the distal end of the covered support. The covered support also includes a first axial line and a second axial line parallel to the longitudinal central axis of the main support. The first axial line passes through the first connection point and intersects the circumferential connection at a second connection point. The second axial line intersects the window at a third connection point and a fourth connection point. The third connection point is located on the distal end side of the fourth connection point. The axial distance between the first connection point and the third connection point is less than the axial distance between the second connection point and the fourth connection point.

2. The covered stent according to claim 1, characterized in that, The window is circular or elliptical, the circumferential connection is circular or elliptical, and the geometric center of the circumferential connection is closer to the distal end of the lumen support than the geometric center of the window.

3. The covered stent according to claim 1, characterized in that, The branch support includes a first end, a middle section, and a second end. The first end and the second end are two opposite ends. The middle section is located between the first end and the second end. The circumferential connection is located in the middle section.

4. The covered stent according to claim 1, characterized in that, The main support includes an annular support member, which is arranged along the edge of the window.

5. The covered stent according to claim 1, characterized in that, When the circumferential connection is on the same horizontal plane as the window, the width of the connecting membrane tube in any direction is greater than the distance from the circumferential connection to the window in the same direction.

6. A support system, characterized in that, The stent system includes a covered stent and a delivery device as described in any one of claims 1-5, the delivery device including a semi-binding structure that releasably binds the main stent to radially compress or release the main stent, and the stent system further includes an adjustable bend catheter extending within the lumen of the main stent, the distal end of the adjustable bend catheter entering from the distal end of the main stent and exiting from the branch stent.

7. The support system according to claim 6, characterized in that, The adjustable bend conduit includes an adjustable bend tube and an adjusting member. The adjustable bend tube includes an extension section and an adjustable bend section, with the adjustable bend section located at the distal end of the extension section. The adjustable bend conduit also includes a limiting hole located at the proximal end of the adjustable bend section. The adjusting member includes a distal end and an adjusting section. The distal end of the adjusting member is connected to the distal end of the adjustable bend tube. The adjusting member passes through the limiting hole and extends proximally, thereby forming the adjusting section between the limiting hole and the distal end. The semi-binding structure includes a wrapping member and a detachable bundle diameter member. The detachable bundle diameter member cooperates with the wrapping member to achieve radial constriction and release of the covered stent. The detachable bundle diameter member passes through the gap between the adjusting section and the adjustable bend section.

8. The support system according to claim 7, characterized in that, The limiting hole includes a tubular structure extending axially, with the distal end of the limiting hole extending to the proximal side of the adjustable bend.

9. The support system according to claim 8, characterized in that, The limiting hole is located on the wall of the adjustable bend; Alternatively, the limiting hole is located on the outside of the adjustable bend.

10. The support system according to claim 7, characterized in that, The adjustable bend conduit also includes a limiting buckle, which is disposed on the distal side of the limiting hole and close to the limiting hole, such that a limiting hole is formed between the adjustable bend and the adjusting member between the limiting buckle and the distal end of the limiting hole, and the diameter release member can pass through the limiting hole.

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