A covered stent system

Abstract

The application provides a covered stent system, which comprises a main covered stent, a positioning assembly and a windowing assembly, the windowing assembly comprising a first opening and a second opening, a first reinforcing structure maintaining the first opening and a second reinforcing structure maintaining the second opening; a branch covered stent, the branch covered stent comprising a proximal end limiting support and a distal end limiting support; when the branch covered stent is connected with the main covered stent, the proximal end limiting support and the distal end limiting support are located on the two sides of the second reinforcing structure and are limited in cooperation, and the branch covered stent and a sealing area of the main covered stent are tightly attached to form a sealed connection. The application realizes accurate positioning, stable anchoring and effective sealing of the branch covered stent, effectively prevents the branch covered stent from protruding in the main lumen, thereby reducing the risk of the branch covered stent being twisted, narrowed and occluded, guarantees the operability of the channel for subsequent intervention of the main lumen and the branch lumen, and avoids the branch covered stent from blocking the opening of the adjacent branch artery.

Description

Technical Field

[0001] This invention belongs to the field of covered stent technology, and specifically relates to a covered stent system. Background Technology

[0002] like Figure 1A and Figure 1B As shown, the aortic arch region consists of the ascending aorta 31, brachiocephalic artery 32, left common carotid artery 33, left subclavian artery 34, and descending aorta 35. Aortic dissection is a disease caused by intramural hemorrhage leading to damage to the media of the aorta, resulting in the separation of the vessel walls and the subsequent formation of interconnected or non-interconnected true lumens 36 and false lumens 37. In most cases, aortic dissection begins with an intimal tear, through which blood enters the media, eventually leading to rupture of the aorta or re-entering the true lumen through a second intimal tear. Based on the location of the dissection, aortic dissection is classified into Stanford type A dissection (dissection involving the ascending aorta), Stanford type B dissection (dissection involving only the descending aorta), and non-A / non-B type dissection (dissection involving the aortic arch but not the ascending aorta).

[0003] For type A aortic dissection and non-type A / non-B aortic dissection, because the lesion involves three branches of the ascending aorta and aortic arch, and the structural relationships between the main trunk and branches in this area vary from patient to patient—including the location of branch openings, the distance between branches, and the direction of branch openings—there is currently no standardized interventional stent product suitable for lesions involving two or more branches and that addresses these differences. Therefore, open-chest surgery under cardiopulmonary bypass remains the conventional approach. However, this surgical approach presents the following challenges:

[0004] 1) The surgical procedure is complex, time-consuming, and not easily promoted: such as Figure 2 As shown, the surgery needs to be performed under cardiopulmonary bypass. The surgeon dissects and removes the entire aortic arch, replaces it with an artificial blood vessel (4), and completes end-to-end sutures between the artificial and autologous blood vessels at at least five sites (ascending aorta (41), brachiocephalic artery (42), left common carotid artery (43), left subclavian artery (44), and descending aorta (45). The surgery takes approximately 6-10 hours, with cardiopulmonary bypass averaging 2-3 hours, aortic clamping averaging 1.5-2 hours, and deep hypothermic circulatory arrest averaging 20-30 minutes. In short, the procedure is complex, time-consuming, and requires a long learning curve for surgeons, making it difficult to promote widely.

[0005] 2) Deep hypothermia with prolonged circulatory arrest can easily lead to ischemia of organs and lower limbs: Deep hypothermia with an average circulatory arrest time of 20-30 minutes can easily cause ischemic and hypoxic damage to various organs, and deep hypothermia can easily lead to pathophysiological changes in various organs.

[0006] 3) The end-to-end suturing of the above-mentioned parts is difficult, the anastomosis is prone to bleeding, and there is a lot of bleeding at the junction of the free original arch serosa; all of the above make hemostasis difficult.

[0007] With the increasing number of hypertension patients worldwide, the prevalence of the aforementioned diseases is also rising annually. Due to these characteristics, many patients cannot receive timely treatment locally and thus lose their lives, making this disease a long-standing challenge for clinicians. For over a decade, doctors around the world have repeatedly attempted to use interventional endovascular repair techniques to treat the condition and alleviate the aforementioned clinical difficulties. The main methods are as follows:

[0008] 1) In situ fenestration technique: A straight cylindrical thoracic aortic endovascular stent graft is implanted into the aortic arch region via a catheter. The endovascular stent graft is ruptured in situ at the corresponding positions of the three branch vessels on the aortic arch. The rupture site is then balloon-dilated. Through the dilated rupture site, the corresponding branch endovascular stent grafts are implanted one by one via a catheter. This technique has the following problems: a) Perforating the main covered stent is an off-label use, and the perforation location may be inaccurate. The balloon dilation opening may be too large or too small, and balloon dilation may also cause tearing of the surrounding covered stent. These problems may lead to twisting, stenosis, or occlusion of the branch covered stent protruding into the main lumen, or endoleak (blood flowing out from the perforation on the main covered stent and the gap between the branch covered stent), resulting in continuous expansion of the false lumen and ultimately requiring a second surgery; b) The branch covered stent protruding into the main lumen may affect the operability of subsequent interventions in the main lumen and branch lumen; c) The branch covered stent protruding into the main lumen may block the opening of the adjacent branch artery, causing cerebral or upper limb ischemia; d) After implantation of the main covered stent but before perforation, the corresponding branch vessel opening is isolated by the main covered stent and is in an ischemic state. If the ischemic state is prolonged, it may cause cerebral infarction.

[0009] 2) Embedded tunnel and modular bridging technique: A thoracic aortic stent graft with three internal tunnels is implanted into the aortic arch region via catheter. These three internal tunnels serve as the interface for bridging the thoracic aortic stent graft and the branch stent graft. The internal tunnels corresponding to the brachiocephalic artery and the left common carotid artery extend from the root of their respective branch vessels toward the ascending aorta, while the internal tunnel corresponding to the left subclavian artery extends from the root of the left subclavian artery toward the descending aorta. The catheter is used to implant the branch stent grafts corresponding to the brachiocephalic artery and the left common carotid artery one by one through the upper access, and the branch stent graft corresponding to the left subclavian artery is implanted through the femoral artery access (referred to as the lower access in interventional medicine). This type of technology also has the following problems: a) A long section (≥15mm) of the branch covered stent is located in the lumen of the main covered stent, which affects the operability of subsequent interventions in the main lumen and branch lumen; b) The branch covered stents of the brachiocephalic artery and the left common carotid artery are implanted through the upper access, which not only makes the operation time longer and more difficult, but also makes many operations possible in the branch vessels, which can easily cause the original plaque in the branch vessels to detach and lead to intraoperative cerebral infarction, or cause damage to the intima of the branch vessels, forming plaques that eventually detach and lead to cerebral infarction.

[0010] The above methods have drawbacks such as long operation time, complex operation, various complications, lack of standardization of instruments and surgical methods, and inability to be promoted in most hospitals. Summary of the Invention

[0011] In view of the shortcomings of the prior art, the purpose of this invention is to provide a covered stent system that enables precise positioning of the branch covered stent during surgery and avoids displacement of the branch covered stent caused by withdrawal of the delivery system during surgery. It can effectively prevent the branch covered stent from protruding into the main lumen, reduce the risk of branch covered stent twisting, stenosis, and occlusion, and ensure the operability of the main lumen and branch lumen for subsequent interventions, avoiding obstruction of the opening of adjacent branch arteries.

[0012] To achieve the above and other related objectives, the present invention provides a covered stent system, comprising:

[0013] a. A master overcoating scaffold, comprising:

[0014] i. A positioning component;

[0015] ii. A branch vessel fenestration assembly, the branch vessel fenestration assembly including a sealing area and an adjustment area; the sealing area including a third opening;

[0016] The adjustment area includes a first opening, a second opening, a first reinforcing structure, and a second reinforcing structure;

[0017] b. A branched covered stent for deployment within the branched vessel fenestration assembly;

[0018] The branched covered stent includes, along its axial direction, a proximal limiting stent, a distal limiting stent, a transition stent, a vascular anchoring stent, and a branched covering over each stent.

[0019] When the branch-covered stent is connected to the main-covered stent, the proximal end limiting stent and the distal end limiting stent are located on both sides of the second reinforcing structure and cooperate to limit the movement, and the branch-covered stent is tightly fitted with the sealing area to form a sealed connection.

[0020] In one embodiment of the present invention, the diameter or area at the distal end apex of the proximal end limiting bracket is larger than the diameter or area at the proximal end apex.

[0021] The diameter or area at the distal end vertex is greater than the diameter or area of ​​the second reinforcing structure;

[0022] The diameter or area at the distal end vertex is smaller than the diameter or area of ​​the first reinforcing structure.

[0023] In one embodiment of the present invention, the diameter or cross-sectional area of ​​the metal wire of the proximal limiting stent is greater than the diameter or cross-sectional area of ​​the metal wire of the distal limiting stent, the transition stent, and the vascular anchoring stent.

[0024] In one embodiment of the present invention, the diameter or area of ​​the proximal limiting bracket gradually increases along the direction from the proximal end to the distal end;

[0025] Alternatively, the segment may include a constant diameter segment and a variable diameter segment along the direction from the proximal end to the distal end, wherein the diameter or area of ​​the variable diameter segment gradually increases along the direction from the proximal end to the distal end.

[0026] Alternatively, the distal end of the proximal limiting bracket is radially outward.

[0027] In one embodiment of the present invention, the diameter or area at the proximal vertex of the distal end limiting bracket is larger than the diameter or area at the distal end vertex.

[0028] The diameter or area at the proximal vertex is greater than the diameter or area of ​​the second reinforcing structure;

[0029] The diameter or area at the distal end vertex is greater than the diameter or area of ​​the sealing area.

[0030] In one embodiment of the present invention, there is a gap of 0.1 mm to 10 mm between the distal end vertex of the proximal end limiting bracket and the proximal end vertex of the distal end limiting bracket.

[0031] In one embodiment of the present invention, the diameter or area of ​​the distal end limiting bracket gradually increases along the direction from the distal end to the proximal end;

[0032] Alternatively, the distal limiting bracket may include a constant diameter section and a variable diameter section along the proximal-distal direction, wherein the diameter or area of ​​the variable diameter section gradually increases along the proximal direction.

[0033] Alternatively, the proximal end of the distal limiting bracket is radially outward.

[0034] In one embodiment of the present invention, the proximal end of the distal limiting stent and the distal end of the proximal limiting stent are respectively provided with a free segment, the free segment is free from the branch covering film, and the height of the free segment is between 0.1mm and 4mm.

[0035] In one embodiment of the present invention, the diameter or area at the proximal apex of the transition stent is equal to the diameter or area at the distal apex of the distal limiting stent, and the diameter or area at the distal apex of the transition stent is equal to the diameter or area at the proximal apex of the vascular anchoring stent.

[0036] In one embodiment of the present invention, the vascular anchoring stent is a plurality of independent stent rings or a single spirally ascending stent ring.

[0037] In one embodiment of the present invention, the branched membrane includes a branched reinforcing membrane, the thickness and / or density of which is greater than the remainder of the branched membrane, and the branched reinforcing membrane at least covers the entire proximal limiting stent.

[0038] In one embodiment of the present invention, the branch-coated stent further includes a first imaging structure and a second imaging structure. The first imaging structure is mounted on the proximal limiting stent and at least covers a portion of the proximal limiting stent. The second imaging structure is mounted on the distal limiting stent and at least covers a portion of the distal limiting stent.

[0039] In one embodiment of the present invention, the first developing structure and the second developing structure are spiral metal structures wound around the limiting bracket.

[0040] In one embodiment of the present invention, the first imaging structure is wound around all of the proximal end limiting brackets, or around a portion of the proximal end limiting brackets, or around the proximal end limiting bracket located at the end.

[0041] This invention proposes a covered scaffold system, which has the following beneficial effects:

[0042] The branched covered stent design in this invention includes a proximal limiting stent and a distal limiting stent, which cooperate with the second reinforcing structure on the second opening of the main covered stent. This allows for precise positioning of the branched covered stent during surgery and prevents stent displacement caused by retraction of the delivery system during the procedure. In summary, this design effectively prevents the branched covered stent from protruding into the main lumen, reduces the risk of stent kinking, stenosis, and occlusion, ensures the operability of subsequent interventions in the main and branch lumen channels, and avoids obstruction of the openings of adjacent branch arteries.

[0043] In this invention, the branch-covered stent has a distal end limiting bracket, which fits into the sealing area of ​​the window opening component of the main covered stent, effectively preventing internal leakage between the main covered stent and the branch-covered stent.

[0044] The proximal and distal limiting stents of the branched covered stent in this invention have imaging structures, which can clearly show the position of the stent under X-ray during delivery, facilitating the intraoperative positioning of the branched covered stent of this invention. Attached Figure Description

[0045] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0046] Figure 1A A schematic diagram showing a normal aorta.

[0047] Figure 1B A schematic diagram showing aortic dissection.

[0048] Figure 2 This demonstrates five instances of end-to-end suturing of artificial and autologous blood vessels during surgical procedures.

[0049] Figure 3 This is a front view of a film-coated support with a window opening assembly.

[0050] Figure 4 This is the front view of the window component.

[0051] Figure 5 This is a top view of the window component.

[0052] Figure 6 This is a schematic diagram of a branched covered stent.

[0053] Figure 7 This is a schematic diagram of the proximal end of a branched covered stent.

[0054] Figure 8 This is a schematic diagram of a proximal limiting stent.

[0055] Figure 9 This is a schematic diagram of a proximal limiting stent in another embodiment.

[0056] Figure 10 This is a schematic diagram of a distal limiting bracket.

[0057] Figure 11 This is a schematic diagram of the distal end limiting bracket in another embodiment.

[0058] Figure 12 This is a schematic diagram of the fenestration assembly aligned with the root of the left common carotid artery and the middle section.

[0059] Figure 13 This is a schematic diagram of the release of the main film-coated stent.

[0060] Figure 14 This is a schematic diagram of a branched covered stent mounted in a delivery system positioned on the left common carotid artery.

[0061] Figure 15 This is a schematic diagram of the deployment of a endovascular stent graft in a branch of the left common carotid artery.

[0062] Figure 16 This is a schematic diagram of adjusting the position of the branch-covered support.

[0063] Figure 17 This is a schematic diagram of the complete release of the endovascular stent graft in the left common carotid artery branch.

[0064] Figure 18 This is a schematic diagram of positioning a branched covered stent, which is mounted in a delivery system, onto the brachiocephalic artery. Detailed Implementation

[0065] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0066] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0067] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention.

[0068] Diseases involving both main and branch blood vessels are currently considered the most life-threatening cardiovascular diseases, requiring emergency transfer to large cardiac centers for highly invasive surgery to achieve treatment. Patients often lose their lives due to delayed treatment. Furthermore, even with timely treatment, the surgical mortality rate is as high as 10%-33%, and the incidence of postoperative complications is as high as 4%-30%. This has long been a major challenge in the clinical treatment of such patients. The main beneficial effects of this invention are as follows:

[0069] 1) It can replace most of the open-heart or open-abdomen surgery that currently requires deep hypothermic circulatory arrest under cardiopulmonary bypass. It only requires catheter intervention to treat related diseases, greatly reducing trauma and the high surgical mortality and high complication rate caused by surgery. It has created a brand-new treatment method for treating diseases involving branch vessels.

[0070] 2) The above-mentioned innovative inventions can all be implanted via lower limb artery intervention. The devices of this invention are simple to operate, easy to learn, and easy to promote to most intermediate hospitals. This changes the current situation where such patients need to be sent to large hospitals hundreds of kilometers away for emergency surgery. It enables many patients to receive timely and rapid treatment in local hospitals, which greatly improves the survival rate of such patients.

[0071] 3) The use of catheter-based interventional methods and instruments to treat vascular diseases involving branch vessels is far less expensive than surgical treatment, and has significant clinical and social implications.

[0072] For the treatment of diseases involving both the main and branch vessels, this invention provides a covered stent with a fenestration component. This covered stent, combined with a branch covered stent, can reconstruct the diseased vessel. For example, in patients with type A and non-type A and non-B dissections (including aneurysms, intramural hematomas, and multiple penetrating ulcers in this area), the covered stent system provided by this invention can reconstruct the diseased aortic arch region.

[0073] Please see Figure 3 , Figure 4 and Figure 5As shown, the present invention provides a film-coated support system. The film-coated support system includes a main film-coated support, which comprises: at least one window assembly 11, a columnar film 12, and a support ring assembly 13. The window assembly 11 consists of a sealing area 111, an adjustment area 112, a first opening 1121, a second opening 1122, a third opening 1112, a first reinforcing structure 113, a second reinforcing structure 114, a first main developing structure 115, a second main developing structure 116, and a third main developing structure 117. The third main developing structure 117 is an optional component.

[0074] Please see Figure 3 , Figure 4 and Figure 5 As shown, the main covered stent 1 with a fenestration assembly is used to treat vascular diseases involving the main and branch vessels. It is an assembly composed of multiple components through a specific process, and includes at least one fenestration assembly 11. The fenestration assembly 11 is the connection structure between the main covered stent 1 with the branch covered stent, and is an assembly composed of multiple components through a specific process.

[0075] The columnar coating 12 is a flexible cylindrical or frustum-shaped thin film attached to the scaffold ring 13 by means of sewing or heat fusion, and its material is a biocompatible material.

[0076] The support ring 13 is a wavy or mesh-like wire frame.

[0077] Please see Figure 3 , Figure 4 and Figure 5 As shown, the sealing area 111 extends from the second reinforcing structure to the third opening 1112, with the extension extending from the second reinforcing structure towards the adjustment area 112. The sealing area 111 is a flexible cylindrical or frustum-shaped film extending upwards, attached to the second opening 1122 of the adjustment area 112 by means of stitching or heat fusion, and its material is a biocompatible material. Its height is between 0.1mm and 10mm, preferably between 1mm and 5mm. This height design takes into account both sealing effect and delivery performance. If the height is too small (less than 0.1mm), it may lead to insufficient sealing and increase the risk of internal leakage; if the height is too large (greater than 10mm), it may increase the overall compression outer diameter of the system, affecting delivery throughput, or causing stress concentration in tortuous blood vessels.

[0078] In one embodiment, the sealing area 111 extends from the second reinforcing structure to the third opening 1112, the extension being an extension from the second reinforcing structure in another direction toward the adjustment area 112.

[0079] In one embodiment, the sealing area 111 extends from the second reinforcing structure to the third opening 1112, the extension being simultaneously from the second reinforcing structure toward the adjustment area 112 and in another direction.

[0080] The adjustment zone 112 is a flexible cylindrical or frustum-shaped thin film attached to the columnar coating 12 by means of sewing or heat fusion, with a first opening 1121 and a second opening 1122 at both ends, and its material is a biocompatible material.

[0081] The first opening 1121 is the opening of the adjustment area 112 on the side near the columnar covering film 12, and its shape is circular or similar to a circle.

[0082] The second opening 1122 is an opening on the side of the adjustment area 112 away from the columnar covering film 12. Its shape is circular or similar to a circle, and its diameter or circumference is smaller than that of the first opening 1121.

[0083] The third opening 1112 is the opening on the side of the sealing area 111 away from the adjustment area 112. Its shape is circular or similar to a circle, and its diameter or circumference is less than or equal to the diameter or circumference of the second opening 1122.

[0084] The first reinforcing structure 113 is a ring-shaped metal attached to the first opening 1121 by means of sewing or hot melting. Its material is superelastic, such as nickel-titanium alloy, and has a certain degree of imaging effect.

[0085] The second reinforcing structure 114 is a ring-shaped metal attached to the second opening 1122 by means of sewing or hot melting. Its material is superelastic, such as a nickel-titanium alloy, and has a certain degree of imaging effect. Preferably, the second reinforcing structure 114 is located inside the second opening 1122.

[0086] The first imaging structure 115 is a spiral metal attached to the first reinforcing structure 113 by a winding method. Its material has good imaging properties under X-rays, such as platinum alloy or gold. Optionally, the first primary imaging structure 115 is located at the center of the cross-section of the first reinforcing structure 113, such as... Figure 7 As shown.

[0087] The second imaging structure 116 is a spiral metal attached to the second reinforcing structure 114 by a winding method. Its material has good imaging properties under X-rays, such as platinum alloy or gold. Optionally, the second main imaging structure 116 is located at the center of the cross-section of the second reinforcing structure 114, such as... Figure 7 As shown.

[0088] The third main imaging structure 117 is a ring or disc-shaped metal attached to the adjustment area 112 by means of sewing or hot melting. The material has good imaging effect under X-ray, such as platinum alloy or gold.

[0089] In one embodiment, the blood vessel is the aortic arch, and the locating branch vessel or the first branch vessel is selected from one of the left common carotid artery, the brachiocephalic artery, and the left subclavian artery.

[0090] In one embodiment, the blood vessel is the abdominal aorta, and the locating branch vessel or the first branch vessel is selected from one of the celiac trunk, left renal artery, right renal artery and superior mesenteric artery.

[0091] In one embodiment, the blood vessel is the aortic root and the ascending aorta, and the locating branch vessel or the first branch vessel is selected from one of the left coronary artery and the right coronary artery.

[0092] In one embodiment, the blood vessel is any artery or vein with two or more branches, and the locating branch vessel or the first branch vessel is selected from one of the branches of the blood vessel.

[0093] The fenestration component 11, as a structure connected to the branch covered stent, can be combined with the branch covered stent when the columnar covered stent 12 and the stent ring 13 are fixed in the main blood vessel, adapting to different vascular anatomy structures.

[0094] The columnar covering 12 ensures that blood flow does not leak to the outside of the covered stent, and together with the stent ring 13, it can seal the vascular intima rupture or the aneurysm cavity.

[0095] The stent ring 13 provides radial support, which allows the columnar cladding 12 to be stably supported in the main blood vessel and supports the function of expanding the true lumen and narrowing the false lumen.

[0096] The sealing area 111 ensures the sealing between the branch film support and the window assembly 11, reducing internal leakage.

[0097] The adjustment zone 112 allows the second opening 1122 to move and rotate within a certain range to adapt to different branch vascular anatomy structures.

[0098] The first opening 1121 allows blood to flow into the regulation zone 112.

[0099] The second opening 1122 allows blood to flow into the sealed area 111.

[0100] The third opening 1112 allows blood to flow out of the sealed area 111.

[0101] The first reinforcing structure 113 maintains the shape of the first opening 1121, ensures unobstructed blood flow to the branch vessels during and after the operation, and facilitates superselection during the operation.

[0102] The second reinforcing structure 114 maintains the shape of the second opening 1122, ensures unobstructed blood flow to the branch vessels during and after the operation, and facilitates superselection during the operation.

[0103] The first primary imaging structure 115 makes the shape of the first opening 1121 more obvious under intraoperative X-ray, thereby facilitating the intraoperative positioning of the primary covered stent 1 with fenestration components, the superselection of branches, and the positioning of branch covered stents.

[0104] The second primary imaging structure 116 makes the shape of the second opening 1122 more obvious under intraoperative X-ray, thereby facilitating the intraoperative positioning of the primary covered stent 1 with fenestration components, the superselection of branches, and the positioning of branch covered stents.

[0105] The third primary imaging structure 117 makes the position of the fenestration component 11 more obvious under intraoperative X-ray, thereby facilitating the intraoperative positioning of the main covered stent 1 with the fenestration component, the superselection of branches, and the positioning of the branch covered stent.

[0106] In one embodiment, the positioning component includes a positioning sealing area and a positioning adjustment area; the positioning sealing area includes a positioning third opening; the positioning adjustment area includes a positioning first opening, a positioning second opening, a positioning first reinforcing structure, and a positioning second reinforcing structure.

[0107] In one embodiment, the covered stent further includes a positioning branch covered stent for implanting the positioning component. The present invention further provides a method for implanting a covered stent into a blood vessel, the blood vessel including a main trunk, a positioning branch vessel, and a first branch vessel.

[0108] In one embodiment, the method includes the following steps: a) providing a covered stent system according to the present invention; b) delivering the covered stent to the main trunk of the blood vessel; c) aligning the positioning component with the positioning branch blood vessel; d) releasing the covered stent so that the covered stent adheres to the inner wall of the main trunk and the positioning component is aligned with the root of the positioning branch blood vessel; e) delivering the branch covered stent to the first branch blood vessel through the branch blood vessel fenestration component 11; f) releasing the branch covered stent so that the second opening is aligned with the root of the first branch blood vessel, and so that the sealing area 111 is in planar sealing connection with the branch covered stent.

[0109] In one embodiment, the blood vessel is the aortic arch, and the locating branch vessel or the first branch vessel is selected from one of the left common carotid artery, the brachiocephalic artery, and the left subclavian artery.

[0110] In one embodiment, the blood vessel is the abdominal aorta, and the locating branch vessel or the first branch vessel is selected from one of the celiac trunk, left renal artery, right renal artery and superior mesenteric artery.

[0111] In one embodiment, the blood vessel is the aortic root and the ascending aorta, and the locating branch vessel or the first branch vessel is selected from one of the left coronary artery and the right coronary artery.

[0112] In one embodiment, the blood vessel is any artery or vein with two or more branches, and the locating branch vessel or the first branch vessel is selected from one of the branches of the blood vessel.

[0113] Please see Figure 6 and Figure 7 As shown, in this embodiment, the covered stent system further includes at least one branch covered stent 2 for implantation into branch vessels to maintain their long-term patency and to form a complete blood flow channel in conjunction with the main covered stent. Figure 5 As shown, the branched covered stent sequentially along its axial direction includes: a proximal limiting stent 21, a distal limiting stent 22, a transition stent 23, a vascular anchoring stent 24, and a branched covered stent 25 covering each stent.

[0114] Please see Figure 6 and Figure 7 As shown, in this embodiment, the proximal limiting stent 21 is located at the proximal end of the branch covered stent and is a wavy or mesh-like metal wire frame. Its main function is to cooperate with the second reinforcing structure 114 of the main covered stent 1 after the branch covered stent 2 is released, so as to achieve precise positioning and prevent axial displacement.

[0115] Please see Figure 6 and Figure 7 As shown, in this embodiment, the diameter or area (area refers to the area of ​​the shape enclosed by each vertex) at the distal end of the proximal end limiting stent 21 is larger than the diameter or area at the proximal end vertex. This design allows the proximal end limiting stent 21 to form an outwardly expanding support structure when released, thereby better engaging with the second reinforcing structure 114 of the main covered stent 1 and preventing the branch covered stent 2 from sliding or dislodging towards the main cavity.

[0116] Please see Figure 6 and Figure 7As shown, the diameter or area at the distal apex of the proximal limiting stent 21 is larger than the diameter or area of ​​the second reinforcing structure 114. This design ensures that when the branch covered stent 2 is released, the proximal limiting stent 21 can be securely engaged with the second reinforcing structure 114, preventing displacement or dislodgement due to blood flow impact or other external forces. This design helps ensure a tight connection between the branch covered stent 2 and the main covered stent 1, reducing the risk of endoleak and ensuring the patency of the branch vessels.

[0117] Please see Figure 6 and Figure 7 As shown, the diameter or area at the distal apex of the proximal limiting stent 21 is smaller than the diameter or area of ​​the first reinforcing structure 1113. This design aims to ensure that the branch covered stent 2 can be accurately positioned within the fenestration assembly 11 of the main covered stent 1 without over-expansion that would affect the patency of the main lumen. Through this dimensional design, the branch covered stent 2 can be stably fixed in the target location without obstructing other branch vessels, thereby providing effective branch vessel reconstruction.

[0118] Please see Figure 6 and Figure 7 As shown, the proximal limiting stent 21, as one of the core components for axial limiting in the branch covered stent 2, primarily functions to form a stable fit with the second reinforcing structure 114 on the main covered stent 1 after the branch covered stent is released, preventing the branch covered stent from retracting or dislodging towards the main lumen. To ensure the reliable implementation of this function, the material structure of the proximal limiting stent 21 has been optimized in this invention. Specifically, the diameter or cross-sectional area of ​​the metal wire used in the proximal limiting stent 21 is larger than the diameter or cross-sectional area of ​​the metal wire used in the distal limiting stent 22, the transition stent 23, and the vascular anchoring stent 24.

[0119] Understandably, since the proximal limiting stent 21 is located at a critical position connecting the branch covered stent and the main covered stent, it needs to withstand the impact of blood flow from the main lumen and the reverse tension that may be generated when the delivery system retracts. Therefore, it needs to have higher radial support and deformation resistance. By increasing the diameter or cross-sectional area of ​​its wires, the overall mechanical strength of this stent segment is significantly improved, allowing it to be more stably "locked" on the proximal side of the second reinforcing structure 114 after expansion, forming an effective physical barrier, thereby enhancing structural rigidity and support.

[0120] Compared to the distal limiting stent 22, the transition stent 23, and the vascular anchoring stent 24, the proximal limiting stent 21 plays a primary role in preventing dislodgement. Increasing its wire size can prevent plastic deformation or elastic buckling under high stress conditions, thereby ensuring that the limiting mechanism remains effective throughout the implantation process and long-term postoperative service, and improving limiting reliability.

[0121] This design embodies the functional gradient layout concept of branched covered stents—emphasizing positioning and restraint at the proximal end, and flexibility and apposition at the distal end. Through differentiated wire size configurations, while ensuring high-strength restraint at the proximal end, the flexibility of the distal stent (such as the vascular anchoring stent) is maintained to adapt to the tortuous course of branch vessels and reduce the risk of vascular injury. In a preferred embodiment, the proximal restraint stent 21 uses a nickel-titanium alloy wire with a diameter of 0.15 mm to 0.40 mm, while the distal restraint stent 22, transition stent 23, and vascular anchoring stent 24 use similar materials with a diameter of 0.10 mm to 0.30 mm, thus achieving a good balance between mechanical properties and flexibility.

[0122] In summary, by strengthening the metal wire structure of the proximal limiting stent, this invention significantly improves the stability and safety of the connection between the branch covered stent and the main covered stent, which is an important guarantee for achieving long-term sealing and anti-displacement capability of the system.

[0123] Please see Figure 8 As shown, in a preferred embodiment, the diameter or area of ​​the proximal limiting stent 21 gradually increases from the proximal end to the distal end. This design makes the proximal limiting stent relatively small at the proximal end, facilitating delivery through a catheter, and allows it to gradually expand during release to form a stable support structure. This not only improves the mechanical strength of the stent but also enhances its fit to the vessel wall, reducing the risk of endoleak.

[0124] Please see Figure 9 As shown, in another preferred embodiment, the proximal limiting stent 21 includes a constant diameter section and a variable diameter section along the proximal to distal direction. The constant diameter section maintains a relatively consistent diameter or area to ensure the stability of the stent in certain critical areas; while the variable diameter section gradually increases in diameter or area to provide additional support force, which can improve its support capacity at the distal end while ensuring the stent's flexibility; of course, the distal end of the proximal limiting stent 21 can also be designed to be radially outward to increase its diameter or area at the distal end and improve its support capacity.

[0125] In this embodiment, the distal limiting stent 22 is a wavy or mesh-like metal wire frame. Its main function is to cooperate with the second reinforcing structure 114 of the main covered stent 1 after the branch covered stent 2 is released, so as to achieve precise positioning and prevent axial displacement.

[0126] In this embodiment, the diameter or area of ​​the distal limiting stent 22 at its proximal apex is designed to be larger than that at its distal apex. This design allows the distal limiting stent 22 to form an outwardly expanding support structure upon release, thereby better engaging with the second reinforcing structure 114 of the main covered stent 1 and preventing the branch covered stent 2 from slipping distally or dislodging. For example, in some embodiments, the diameter at the proximal apex of the distal limiting stent 22 can be 18 mm, while the diameter at the distal apex can be reduced to 17 mm. This gradually decreasing design not only enhances the stability of the stent but also improves its ability to adapt to different vascular anatomy structures.

[0127] In this embodiment, the diameter or area at the proximal apex of the distal limiting stent 22 is designed to be larger than the diameter or area of ​​the second reinforcing structure 114 in the main covered stent 1. This design ensures that when the branch covered stent 2 is released, the distal limiting stent 22 can be securely engaged with the second reinforcing structure 114, preventing displacement or dislodgement due to blood flow impact or other external forces. In practical applications, this design helps ensure a tight connection between the branch covered stent 2 and the main covered stent 1, reducing the risk of endoleak and ensuring the patency of the branch vessels.

[0128] In this embodiment, the diameter or area at the distal apex of the distal limiting stent 22 is designed to be larger than the diameter or area of ​​the sealing region 111 in the main covered stent 1. This design aims to ensure that the branch covered stent 2 can be accurately positioned within the fenestration assembly 11 of the main covered stent 1 without over-expansion that would affect the function of the sealing region. Through this dimensional design, the branch covered stent 2 can be stably fixed in the target location without obstructing the sealing region, thereby providing effective branch vessel reconstruction.

[0129] Please see Figure 10 As shown, in a preferred embodiment, the diameter or area of ​​the distal limiting stent 22 gradually increases from the distal end to the proximal end. This design makes the distal limiting stent relatively small at the distal end, facilitating delivery through a catheter, and allows it to gradually expand during deployment to form a stable support structure. This gradually increasing design not only improves the mechanical strength of the stent but also enhances its fit to the vessel wall, reducing the risk of endoleak.

[0130] Please see Figure 11As shown, in another preferred embodiment, the distal limiting stent 22 includes a constant-diameter section and a variable-diameter section along the direction from the distal to the proximal end. The constant-diameter section maintains a relatively consistent diameter or area to ensure the stability of the stent in certain critical areas; while the variable-diameter section gradually increases in diameter or area to provide additional support. This design can improve its support capacity at the proximal end while ensuring the stent's flexibility. Of course, the proximal end of the distal limiting stent 22 can also be designed to curve outward radially to increase its diameter or area at the proximal end and improve its support capacity.

[0131] In this embodiment, a gap of 0.1 mm to 10 mm exists between the distal apex of the proximal limiting stent 21 and the proximal apex of the distal limiting stent 22. This design aims to ensure precise alignment of the branched covered stent 2 during deployment and to provide sufficient flexibility to accommodate different patients' vascular anatomy. The proximal limiting stent 21 and the distal limiting stent 22 are two key support structures in the branched covered stent 2, used to achieve precise docking and stable connection with the main covered stent 1.

[0132] In this invention, a specific gap exists between the distal apex of the proximal limiting stent 21 and the proximal apex of the distal limiting stent 22, with the height of this gap ranging from 0.1 mm to 10 mm. This design ensures that the two limiting stents do not directly contact each other during release, thereby preventing stent deformation or functional failure due to excessive compression. For example, in some embodiments, the height of this gap can be set to 2 mm, which ensures stent stability while providing sufficient flexibility to adapt to differences in vascular anatomy among different patients.

[0133] Understandably, by setting appropriate gaps, the branched covered stent 2 can better adapt to the vascular anatomy of different patients during deployment. Especially in complex vascular environments, such as the aortic arch or abdominal aorta, the presence of gaps allows the stent to adjust its shape and position to a certain extent, reducing pressure on the vessel wall and lowering the risk of postoperative complications.

[0134] It is also understandable that if the proximal limiting stent 21 and the distal limiting stent 22 are in direct contact, it may cause unnecessary deformation of the stent during release, affecting its support effect. By setting a gap, this situation can be effectively avoided, ensuring that the stent maintains its ideal shape after release.

[0135] It is also understandable that the gap design ensures a tight fit between the sealing area 111 of the branch membrane support 2 and the main membrane support 1, preventing internal leakage. In particular, when the support is released, the branch membrane 25 can fully cover the sealing area 111, forming a continuous planar sealing connection, which improves the sealing performance of the system.

[0136] The distal limiting stent 22 and the proximal limiting stent 21 each have a free segment at a specific location. The design of these free segments is intended to enhance the adaptability and stability of the branched covered stent 2 within the blood vessel.

[0137] The distal limiting stent 22 has a free segment near its proximal apex, which is separate from the branch cover 25. The height of the free segment ranges from 0.1 mm to 4 mm. This design allows the distal limiting stent 22 to have a certain degree of freedom during deployment, thereby better adapting to the irregular shape of the vessel wall and ensuring a tight fit with the sealing area 111 to prevent endoleak. In some embodiments, the free segment can be of uniform height or gradually varying height to accommodate different vascular anatomy requirements. For example, in some cases, the height of the free segment can be shorter near the proximal apex and gradually increase further away from the apex to provide better support.

[0138] Similarly, the proximal limiting stent 21 also has a free segment near its distal apex, which is also separate from the branch cover 25. The height of the free segment also ranges from 0.1 mm to 4 mm. This design allows the proximal limiting stent 21 to flexibly adjust its shape during release to better engage with the second reinforcing structure 114 and avoid unnecessary pressure on the main lumen. For example, in some embodiments, the free segment of the proximal limiting stent 21 may be shorter at the distal apex and gradually increase in height closer to the main body to provide better radial support.

[0139] The presence of a free segment allows the stent to better adapt to irregular vessel wall morphologies during deployment, especially in complex vascular anatomy areas such as the aortic arch or abdominal aorta. This design helps reduce stent pressure on the vessel wall and lowers the risk of postoperative complications.

[0140] The free segment of the distal limiting stent 22 is tightly integrated with its sealing area 111, forming a continuous planar sealing connection, effectively preventing internal leakage between the main cavity and the branch cavity. In this way, the sealing performance of the stent system is significantly improved, and the incidence of type Ia internal leakage is reduced.

[0141] The free segment design of the proximal limiting stent 21 and the distal limiting stent 22 makes the branched covered stent 2 more flexible during implantation, facilitating precise operation by the physician. The presence of the free segment allows the stent to have a certain degree of deformation capability during deployment, thus making it easier to achieve accurate positioning and fixation.

[0142] In summary, the distal limiting stent 22 and the proximal limiting stent 21, through their unique free segment design, achieve precise alignment and stable connection of the branched covered stent 2 in complex vascular environments. This design not only enhances the stent's adaptability and stability but also significantly reduces the difficulty of the procedure, improves treatment outcomes, and reduces the incidence of postoperative complications.

[0143] In this embodiment, in the covered stent system of the present invention, the branch covered stent 2, through its unique structural design, achieves precise docking and stable connection with the fenestration assembly 11 on the main covered stent 1. The proximal limiting stent 21 and the distal limiting stent 22 play crucial roles in axial limiting and sealing. Specifically, the proximal limiting stent 21 is a wave-shaped or mesh-shaped metal stent located near the proximal end of the branch covered stent 2, with its diameter or area at the distal end apex being larger than that at the proximal end apex. After the branch covered stent 2 is released and positioned, the proximal limiting stent 21 is located on the proximal side of the second reinforcing structure 114 in the main covered stent 1, forming a mechanical limiting engagement with it. When the delivery system retracts, if the branch covered stent 2 tends to move towards the main cavity, the expanded end of the proximal limiting stent 21 will abut against the second reinforcing structure 114, thereby effectively preventing it from dislodging or shifting into the main cavity. Meanwhile, the distal end limiting bracket 22 is disposed at the distal end of the branch covered stent 2, and its diameter or area at the proximal end apex is larger than that at the distal end apex. After release, the distal end limiting bracket 22 is located on the distal end side of the second reinforcing structure 114, forming a "clamping" limiting structure together with the proximal end limiting bracket 21, stably clamping the second reinforcing structure 114 between the two, further ensuring the axial fixation reliability of the branch covered stent 2.

[0144] Furthermore, the distal limiting stent 22 provides sufficient radial support during radial expansion, ensuring a tight fit between the branch graft 25 it supports and the sealing area 111 of the fenestration assembly 11 in the main graft 1. The sealing area 111 is a flexible membrane structure extending from the second opening 1122, and is cylindrical or frustum-shaped. The planar fit between the branch graft 25 and the sealing area 111 forms a continuous sealing interface, effectively blocking the path of blood leakage from the main lumen through the second opening 1122 to the outside of the branch graft stent, thereby preventing endoleak.

[0145] In summary, by combining the synergistic limiting effect of the proximal limiting stent 21 and the distal limiting stent 22 with the second reinforcing structure 114, and the compression and sealing function of the distal limiting stent on the sealing area 111, this invention achieves stable anchoring and reliable sealing of the branched covered stent in complex blood flow environments, significantly improving the long-term safety and clinical effectiveness of the covered stent system.

[0146] In this embodiment, the transition stent 23 is a corrugated or mesh-like wire frame and is a key component in the branch covered stent 2 that connects the distal limiting stent 22 and the vascular anchoring stent 24. Its main function is to provide a smooth transition between the two, ensuring that the entire branch covered stent 2 maintains a consistent radial support force during deployment and adapts to the morphological changes of the branch vessels.

[0147] In this embodiment, the diameter or area at the proximal apex of the transition stent 23 is designed to be equal to the diameter or area at the distal apex of the distal limiting stent 22. This design ensures a seamless connection between the two, avoiding stress concentration or stent deformation caused by diameter mismatch. This consistent design not only improves the overall stability of the stent but also enhances its fit to the vessel wall, reducing the risk of endoleak. Similarly, the diameter or area at the distal apex of the transition stent 23 is designed to be equal to the diameter or area at the proximal apex of the vascular anchoring stent 24. This design ensures a smooth transition between the two, avoiding local pressure concentration or stent displacement caused by diameter difference, and this matching design allows the entire branch covered stent 2 to form a continuous and stable support structure after deployment, ensuring the patency of the branch vessel.

[0148] The vascular anchoring stent 24 is a corrugated or mesh-like wire frame. Its diameter or area is larger than that of the implanted blood vessel to ensure that the branch-covered stent 2 provides sufficient radial support within the target branch vessel and achieves stable anchoring. Furthermore, the vascular anchoring stent 24 can be designed as multiple independent stent rings or as a single, integrally molded, spirally ascending stent ring to adapt to the anatomical morphology and clinical needs of different branch vessels.

[0149] The vascular anchoring stent 24 is located at the distal end of the branch covered stent 2. Its main function is to provide sufficient radial support for the branch covered stent, so that it is stably anchored to the inner wall of the branch vessel (such as the left common carotid artery, left subclavian artery or renal artery) to prevent postoperative displacement or endoleak.

[0150] The diameter or area of ​​the vascular anchoring stent 24 is designed to be larger than the diameter or area of ​​the implanted blood vessel to ensure that it can expand sufficiently after release and fit tightly against the vessel wall, thereby ensuring that it can be firmly fixed to the inner wall of the blood vessel after release. This design helps to improve the anchoring effect of the stent and prevent postoperative displacement or endoleak.

[0151] In a preferred embodiment, the vascular anchoring stent 24 comprises multiple independent stent rings arranged at intervals along the axial direction. The stent rings are connected by a covering to form a single integral structure. Each stent ring can employ a wavy, Z-shaped, or mesh wire structure, preferably made of a highly elastic nickel-titanium alloy (Nitinol), which possesses excellent self-expansion properties and biocompatibility. The presence of a certain degree of bending freedom between the multiple independent rings allows the stent to conform to the curvature of the branch vessel, reducing mechanical stimulation to the vessel wall. Each stent ring can independently conform to the inner wall of the vessel, making it particularly suitable for branch vessels with slight curvature or torsion. Furthermore, each stent ring can be individually processed and integrated onto the branch covering 25, resulting in high process controllability.

[0152] In another preferred embodiment, the vascular anchoring stent 24 is a one-piece, spirally ascending stent ring, meaning the entire stent is formed by a single metal wire spiraling upwards in the circumferential direction to create a continuous support structure. This spiral structure can be designed with a constant pitch or a variable pitch to accommodate branch vessels of different lengths and diameters. This design provides excellent balance between axial flexibility and radial support force. The spiral structure provides sufficient radial force while allowing the stent to deform freely in curved vessels, avoiding stress concentration; the one-piece spiral provides continuous support along the vessel axis, enhancing the overall anchoring effect.

[0153] The branch cover 25 is a flexible columnar film attached to the proximal limiting stent 21, the distal limiting stent 22, the transition stent 23, and the vascular anchoring stent 24 by means of suturing or thermal fusion. The material is a biocompatible material.

[0154] The proximal opening 251 is the proximal opening of the branch graft 25, and its shape is circular or similar to a circle. Blood flows into the branch graft stent through this opening.

[0155] The distal opening 252 is the distal opening of the branch graft 25, which is circular or similar in shape, through which blood flows out of the branch graft stent.

[0156] The branched covering 25 includes a branched reinforcing covering 253, which has enhanced mechanical properties to improve the tear resistance and connection stability of the proximal region of the branched covering stent 2.

[0157] Specifically, the thickness and / or material density of the branch-reinforced cover 253 is greater than that of the rest of the branch cover 25, increasing its strength and bonding strength with the stent. This prevents the stent from detaching from the cover and also prevents damage to the cover during intraoperative positioning of the branch-covered stent 2. This localized thickening or densification design is mainly used to withstand stress concentration from the proximal end during implantation and long-term postoperative service, especially in the area where it docks with the fenestration component 11 of the main covered stent 1, avoiding damage or peeling of the cover due to friction, blood flow impact, or radial expansion force.

[0158] Furthermore, the branch-reinforced membrane 253 at least completely covers the proximal limiting stent 21. In a preferred embodiment, its coverage extends axially from the proximal end of the proximal limiting stent 21 to a portion of the transition stent 23, ensuring that the entire limiting structure is wrapped in a high-strength membrane. This design not only improves the overall strength of the proximal structure but also enhances the sealing reliability between the proximal structure and the main membrane stent sealing area 111, preventing internal leakage caused by membrane deformation or tearing.

[0159] In terms of material selection, the branch-reinforced coating 253 can use the same material as the main branch coating (such as ePTFE, PET, or polyurethane), but its performance is enhanced through the following methods:

[0160] Multilayer stacking: stacking two or more layers of thin film by hot pressing or sewing to form a locally thickened area;

[0161] High-density sintering: Sintering ePTFE materials at higher temperatures or pressures to improve fiber density per unit volume.

[0162] Please see Figure 6 and Figure 7 As shown, in this embodiment, the branch-covered stent 2 further includes a first imaging structure 26 and a second imaging structure 27, which are used to clearly display the position of key structures under X-ray fluoroscopy, making the shapes of the proximal limiting stent 21 and the distal limiting stent 22 more obvious under intraoperative X-ray, thereby facilitating the intraoperative positioning of the branch-covered stent 2 and achieving precise intraoperative positioning and alignment.

[0163] Please see Figure 6 and Figure 7As shown, the first imaging structure 26 is mounted on the proximal limiting stent 21 and covers at least a portion of the stent. Preferably, the first imaging structure 26 is spirally wound or segmentally wrapped around the metal wire of the proximal limiting stent 21 to ensure its uniform distribution throughout the circumference of the stent. It can be understood that the first imaging structure 26 is wound around the entire proximal limiting stent 21, or around a portion of the proximal limiting stent 21, or around the proximal limiting stent 21 located at the end. This design allows the physician to accurately identify the spatial position and orientation of the proximal limiting stent 21 through the imaging system during interventional surgery, especially when the branch covered stent 2 is inserted into the branch vessel through the fenestration assembly 11 of the main covered stent 1, facilitating the determination of whether it is aligned with the target vessel opening and completing precise release.

[0164] Please see Figure 6 and Figure 7 As shown, the second imaging structure 27 is mounted on the distal limiting stent 22 and covers at least a portion of the stent. It is understood that the second imaging structure 27 is wound around the entire distal limiting stent 22, a portion of the distal limiting stent 22, or the distal limiting stent 22 located at the end. Similarly, the second imaging structure 27 may be positioned along the wavy or mesh metal frame of the distal limiting stent 22 to provide a clear outline under X-rays. This imaging structure helps confirm whether the distal end of the branch-covered stent 2 has fully entered the target branch vessel, whether it has shifted or twisted, and verifies the accuracy of its anchoring position.

[0165] The aforementioned imaging structures are typically made of high-density, biocompatible noble metal materials, such as platinum (Pt), platinum-iridium alloy (Pt-Ir), gold (Au), or tantalum (Ta), which have excellent X-ray blocking capabilities and can achieve high-contrast imaging under low-dose radiation conditions. By setting up the first and second imaging structures, this invention enables visual monitoring of two key limiting structures at both ends of the branched covered stent, significantly improving the safety and success rate of surgical procedures.

[0166] Please see Figure 6 and Figure 7 As shown, both the first imaging structure 26 and the second imaging structure 27 are spiral metal structures wound around the limiting bracket. Specifically, the first imaging structure 26 is spirally wound in the form of fine filaments around the metal skeleton of the proximal limiting bracket 21, and is distributed continuously or intermittently along its circumference. Similarly, the second imaging structure 27 is also spirally wound around the surface of the metal wires of the distal limiting bracket 22 in the same manner. This spiral winding structure has the following advantages:

[0167] Uniform development: The spiral distribution ensures that the developing material continuously covers the entire circumference of the support, avoiding image interruption due to local missing parts, and improving the continuity and recognizability of the contour under X-ray.

[0168] Without affecting the performance of the stent: The stent is wound with fine-diameter precious metal wire (such as platinum-iridium alloy wire with a diameter of 0.025–0.10 mm), which provides good imaging effect without significantly increasing the compressible outer diameter of the stent or affecting its self-expansion performance.

[0169] Firm bonding: The developing wire is tightly bonded to the nickel-titanium alloy support frame through a heat setting process to prevent slippage or detachment due to friction or bending during transportation;

[0170] Good compliance: The spiral structure itself is elastic and can stretch and contract synchronously with the deformation of the stent in the curved blood vessel, maintaining the integrity of the imaging signal;

[0171] Mature manufacturing process: Spiral winding is a mature processing method for developing structures in the field of coated stents, which is easy to achieve mass production and quality control.

[0172] In a preferred embodiment, the first imaging structure 26 spirally wraps around and covers the entire annular structure of the proximal limiting stent 21, while the second imaging structure 27 covers all or most of the support segments of the distal limiting stent 22, ensuring high visibility for both the proximal and distal limiting stents. This spirally wrapped imaging structure design not only significantly improves the visibility of the branched covered stent during intervention but also balances mechanical properties, flexibility, and manufacturing feasibility, providing a crucial technical guarantee for achieving minimally invasive and precise implantation.

[0173] In summary, the technical problems to be solved by this invention are as follows:

[0174] The branch-covered stent design includes a proximal limiting stent 21 and a distal limiting stent 22, which cooperate with the second reinforcing structure 114 on the second opening 1122 of the main covered stent. This allows for precise positioning of the branch-covered stent during the procedure and prevents stent displacement caused by retraction of the delivery system. In summary, this design effectively prevents the branch-covered stent from protruding into the main lumen, reduces the risk of stent kinking, stenosis, and occlusion, ensures the accessibility of subsequent interventions in the main and branch lumen, and avoids obstruction of the openings of adjacent branch arteries.

[0175] The branch-covered stent has a distal end limiting bracket 22, which fits into the sealing area 111 of the window assembly of the main covered stent, effectively preventing internal leakage between the main covered stent and the branch-covered stent.

[0176] The proximal limiting stent 21 and distal limiting stent 22 of the branch covered stent have imaging structures, which can clearly show the position of the stent under X-ray during delivery, facilitating the intraoperative positioning of the branch covered stent of the present invention.

[0177] The adjustment area 112 of the fenestration component of the main covered stent allows the position and angle of the second opening 1122 of the fenestration component to move and adjust within a certain range to adapt to the anatomical differences in most main trunk and branch vessels.

[0178] The structure of the fenestrated component of the main covered stent does not restrict the access position of the branch covered stent system. All branch covered stents can be implanted through the femoral artery (lower access). This avoids the postoperative brain complications that may be caused by plaque detachment from the inner wall of the branch vessel when using techniques such as embedded tunnels and modular bridging from the upper access. It can shorten the operation time, facilitate the operation of doctors, and promote the promotion of the surgery.

[0179] The fenestration of the main covered stent has a reinforced structure. After the covered stent is implanted into the blood vessel, it can isolate the blood vessel wall and the lesion site (false lumen, hematoma, etc.). Even when the blood vessel is compressed, it can maintain the shape of the fenestration, maintain the blood flow of the branch vessels, and facilitate the superselection of the guidewire during the operation, solving the problem of cerebral blood supply that may exist in other techniques.

[0180] The fenestration component of the main covered stent has a radiopaque structure, which can clearly show the position of the fenestration component under X-ray during the delivery and superselection of the main covered stent, facilitating the intraoperative positioning of the covered stent, the superselection of the guidewire, and the intraoperative positioning of the branch covered stent.

[0181] The above features of the present invention are suitable for the repair and reconstruction of most lesions with anatomical differences in the main trunk and branch vessels (including dissecting aneurysms, true aneurysms, intramural hematomas, and multiple penetrating ulcers), such as the aortic arch and the three branches above the arch, as well as the abdominal aorta and the left and right renal arteries, superior mesenteric artery, and celiac trunk artery, etc.

[0182] Please see Figures 12 to 17 As shown, in this invention, the surgical procedure for treating vascular diseases involving both the main and branch vessels can be simplified to the following steps. Here, for ease of explanation, the aortic arch region is selected as the area requiring reconstruction:

[0183] 1. Please refer to Figure 12 As shown, the main covered stent 1 is loaded into the delivery system. The main covered stent 1 has three fenestration assemblies 11, which correspond from left to right to the brachiocephalic artery, the left common carotid artery, and the left subclavian artery, respectively. The delivery system is delivered to the designated location by aligning the imaging structures (first main imaging structure 115, second main imaging structure 116, or third main imaging structure 117) in the fenestration assembly 11 at the root of the left common carotid artery and in the middle.

[0184] 2. Please refer to Figure 13As shown, the main covered stent 1 is released into the aorta. At this time, the main covered stent 1 adheres to the inner wall of the aorta, and the fenestration component 11 in the middle is aligned with the root of the left common carotid artery.

[0185] 3. Please refer to Figure 14 As shown, the branch coating support 2 is loaded in the transport system, and the transport system is transported to the designated position by aligning the first main developing structure 115 on the middle window assembly 11 on the main coating support 1 with the distal end of the second developing structure 27 on the branch coating support 2.

[0186] 4. Please refer to Figures 15 to 16 As shown, the first step of releasing the branch stent graft of the left common carotid artery is performed. At this time, the proximal limiting stent 21 and the distal limiting stent 22 are in the larger diameter released state, while the vascular anchoring stent 24 is still in the smaller diameter restrained state. The upward delivery system moves the branch stent graft 2 distally until the second reinforcing structure 114 of the main stent graft 1 is positioned between the proximal limiting stent 21 and the distal limiting stent 22 of the branch stent graft 2. At this time, because the diameter or area at the distal apex of the proximal limiting stent 21 is larger than the diameter or area of ​​the second reinforcing structure 114, and the diameter or area at the distal apex of the proximal limiting stent 21 is larger than the diameter or area at the proximal apex of the proximal limiting stent 21, a limiting effect is formed. If the delivery system is pushed upward further, there will be significant resistance.

[0187] 5. Please refer to Figure 17 As shown, the branch stent graft of the left common carotid artery is fully released. At this time, the distal limiting stent 22 is abutted against the sealing area 111, and the vascular anchoring stent 24 is abutted against the left common carotid artery 33. The delivery system is then withdrawn. During withdrawal, the branch stent graft may be subjected to force and tend to move proximally. Because the diameter or area of ​​the proximal end of the distal limiting stent 22 is larger than the diameter or area of ​​the second reinforcing structure 114, and the diameter or area of ​​the proximal end of the distal limiting stent 22 is larger than the diameter or area of ​​the distal end of the distal limiting stent 22, it forms a limiting force, preventing the branch stent graft from falling into the main lumen. Thus, the proximal limiting stent 21, the distal limiting stent 22, and the second reinforcing structure 114 together limit the position of the branch stent graft 2, ensuring that the branch stent graft 2 neither protrudes into the main lumen nor detaches from the fenestration assembly 11 of the main stent graft 1.

[0188] 6. Please refer to Figure 18As shown, the branch covered stent 2 is loaded into the delivery system. By aligning the first primary imaging structure 115 on the left side of the fenestration assembly 11 on the main covered stent 1 with the distal end of the second imaging structure 27 on the branch covered stent 2, the delivery system is delivered to the designated position. When the second opening 1122 in the leftmost fenestration assembly 11 is misaligned with the root of the brachiocephalic artery 321, the adjustment area 112 in the fenestration assembly 11 allows the second opening 1122 to move and rotate within a certain range. When the guidewire is operated to overselect and push the branch covered stent system, the second opening 1122 can adjust its position and angle to align with the root of the brachiocephalic artery 321.

[0189] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A covered scaffold system, comprising: a. A master overcoating scaffold, comprising: i. A positioning component; ii. A branch vessel fenestration assembly, the branch vessel fenestration assembly including a sealing area and an adjustment area; the sealing area including a third opening; The adjustment area includes a first opening, a second opening, a first reinforcing structure, and a second reinforcing structure; b. A branched covered stent for deployment within the branched vessel fenestration assembly; Its features are: The branched covered stent includes, along its axial direction, a proximal limiting stent, a distal limiting stent, a transition stent, a vascular anchoring stent, and a branched covering over each stent. Wherein, the diameter or area at the distal end apex of the proximal end limiting bracket is larger than the diameter or area at the proximal end apex, which is larger than the diameter or area of ​​the second reinforcing structure, but smaller than the diameter or area of ​​the first reinforcing structure; The diameter or area at the proximal vertex of the distal end limiting bracket is greater than the diameter or area at the distal end vertex, and greater than the diameter or area of ​​the second reinforcing structure, and greater than the diameter or area of ​​the sealing area. When the branch-covered stent is connected to the main-covered stent, the proximal end limiting stent and the distal end limiting stent are located on both sides of the second reinforcing structure and cooperate to limit the movement, and the branch-covered stent is tightly fitted with the sealing area to form a sealed connection. The distal end of the distal limiting stent and the distal end of the proximal end of the proximal limiting stent are respectively provided with a free segment, which is free from the branch covering film, and the height of the free segment is between 0.1mm and 4mm.

2. The covered scaffold system according to claim 1, characterized in that, The diameter or cross-sectional area of ​​the wire in the proximal limiting stent is greater than the diameter or cross-sectional area of ​​the wire in the distal limiting stent, the transition stent, and the vascular anchoring stent.

3. The covered scaffold system according to claim 1, characterized in that, The diameter or area of ​​the proximal limiting bracket gradually increases from the proximal end to the distal end; Alternatively, the segment may include a constant diameter segment and a variable diameter segment along the direction from the proximal end to the distal end, wherein the diameter or area of ​​the variable diameter segment gradually increases along the direction from the proximal end to the distal end. Alternatively, the distal end of the proximal limiting bracket is radially outward.

4. The covered scaffold system according to claim 1, characterized in that, There is a gap of 0.1 mm to 10 mm between the distal end vertex of the proximal end limiting bracket and the proximal end vertex of the distal end limiting bracket.

5. The covered scaffold system according to claim 1, characterized in that, The diameter or area of ​​the distal limiting bracket gradually increases from the distal end to the proximal end; Alternatively, the distal limiting bracket may include a constant diameter section and a variable diameter section along the proximal-distal direction, wherein the diameter or area of ​​the variable diameter section gradually increases along the proximal direction. Alternatively, the proximal end of the distal limiting bracket is radially outward.

6. The covered scaffold system according to claim 1, characterized in that, The diameter or area at the proximal apex of the transition stent is equal to the diameter or area at the distal apex of the distal limiting stent, and the diameter or area at the distal apex of the transition stent is equal to the diameter or area at the proximal apex of the vascular anchoring stent.

7. The covered stent system according to claim 1, characterized in that, The vascular anchoring stent may be multiple independent stent rings or a single spirally ascending stent ring.

8. The covered scaffold system according to claim 1, characterized in that, The branched membrane includes a branched reinforcing membrane, the thickness and / or density of which is greater than the rest of the branched membrane, and the branched reinforcing membrane covers at least the entire proximal limiting stent.

9. The covered stent system according to claim 1, characterized in that, The branch-coated stent further includes a first imaging structure and a second imaging structure. The first imaging structure is installed on the proximal limiting stent and at least covers a portion of the proximal limiting stent. The second imaging structure is installed on the distal limiting stent and at least covers a portion of the distal limiting stent.

10. The covered stent system according to claim 9, characterized in that, The first developing structure and the second developing structure are spiral metal structures wound around the limiting bracket.

11. The covered stent system according to claim 10, characterized in that, The first imaging structure is wound around all or part of the proximal limiting brackets or around the proximal limiting brackets located at the end; the second imaging structure is wound around all or part of the distal limiting brackets or around the distal limiting brackets located at the end.

Images