Blood flow maintaining device and aorta covered stent system

Abstract

The utility model discloses a blood flow maintaining device and an aorta covered stent system.The blood flow maintaining device comprises a conveying sheath and a blood flow maintaining net basket, the conveying sheath comprises a sheath tube, and the blood flow maintaining net basket comprises a net basket and a pushing assembly; the net basket has an unfolded state and a folded state; the pushing assembly is connected with the net basket, and the pushing assembly is used for pushing the net basket in the sheathing canal; when the mesh basket is in an unfolded state after being released outwards from the far-end opening of the sheath tube, the mesh basket is suitable for supporting the aorta covered stent and forming a covered stent external blood flow channel on the outer side of the aorta covered stent. When the blood flow maintaining net basket is applied to an aortic arch intracavity isolation treatment operation, the net basket can ensure that the blood flow of each branch is not interrupted before branch windowing is completed, the requirements for hospital conditions and the operation level of an operator are reduced, the operation time is shortened, meanwhile, postoperative complications are reduced, and operation popularization is facilitated.

Description

Technical Field

[0001] This utility model relates to the field of interventional medical device technology, specifically to a blood flow maintenance device for supra-arch branch vessels and an aortic endovascular stent graft system. Background Technology

[0002] With an aging population and the increasing prevalence of hypertension and arteriosclerosis, the number of patients with aortic disease is rising year by year. Type A aortic dissection, involving the aortic arch, accounts for 70% of aortic dissections, and currently, open surgery remains the primary treatment for these patients. However, open surgery is highly invasive, requiring cardiopulmonary bypass or even deep hypothermic circulatory arrest, and is time-consuming. The longer the surgery, the higher the postoperative complications and mortality rate. Minimally invasive treatment of aortic arch diseases is a new approach to aortic disease management. Currently, endovascular reconstruction of the aortic arch using three (or multiple) branches is generally employed for minimally invasive treatment of aortic arch diseases.

[0003] Currently, endovascular aortic arch repair is mainly used for treating non-major branch segments such as the descending aorta and branch vessels where there are no strict requirements for operation time and blood flow occlusion, such as the thoracic and abdominal aorta, and the abdominal aortoiliac artery. The thoracic aortic arch has three important branch vessels responsible for supplying blood to the brain and upper limbs. The cerebral blood supply occlusion time cannot be too long; ischemia exceeding five minutes generally leads to severe irreversible brain damage due to hypoxia, and may even cause death. The number, diameter, spacing, location, and direction of the branch vessels in the aortic arch vary from person to person, without a clear pattern. These factors dictate that multi-branch covered stents are used. Endovascular aortic arch repair is often insufficient to meet clinical needs because the required number and specifications of branch stents are too large, the operation is difficult, surgical complications are high, and branch blood flow is easily blocked, leading to branch occlusion.

[0004] While the embedded branch combination approach reduces the number of stents required and has some commercial feasibility, it still faces challenges such as complex surgical procedures, intraoperative ischemia, high skill requirements, high complication rates, and difficulty in promoting this technique in ordinary hospitals. Furthermore, the embedded branch reconstruction method alters the location of the branch vessel opening, hindering subsequent minimally invasive interventional treatment of the branch vessels. There is also the issue of insufficient reconstruction of the branch if the embedded branch deviates too much from the original branch's course.

[0005] In-situ fenestration or external fenestration based on the branch location of the aortic endovascular stent graft can effectively address the differences in the number, diameter, spacing, location, and orientation of branch vessel stents. Furthermore, fewer branch vessel stents are required, and the branch inlet is consistent with the original branch vessel inlet, thus not affecting the long-term minimally invasive interventional needs of the branch vessels.

[0006] While in situ fenestration has many advantages and is suitable for complete transaortic arch reconstruction, current in situ fenestration procedures for endovascular repair of all branches of the aortic arch involve the aortic stent graft being deployed within the aortic arch in the chest. This stent graft covers the supra-aortic branches, causing cerebral blood flow interruption before the fenestration reconstruction is complete. This occlusion of the supra-aortic branches by the stent graft leads to intracranial ischemia, resulting in irreversible damage. A five-minute interruption of cerebral blood flow can cause loss of consciousness, irreversible brain damage, and even death. The fact that the aortic stent graft can block the brain during the fenestration process is a major technical challenge preventing the widespread application of in situ fenestration. Current in situ fenestration surgeries for reconstructing all supra-aortic branches require cardiopulmonary bypass or deep hypothermic circulatory arrest to address the problem of cerebral blood flow being blocked by the aortic stent graft before branch reconstruction (cardiopulmonary bypass ensures cerebral blood flow is supplied externally during fenestration reconstruction, preventing cerebral ischemia; deep hypothermic circulatory arrest prolongs the time before brain death due to ischemia under hypothermic conditions). Both extracorporeal circulation and deep hypothermic circulatory arrest techniques place excessive demands on hospital conditions and the skill level of the surgeons, while also leading to a higher complication rate.

[0007] Therefore, designing a blood flow maintenance device that is easy to operate on, promotes surgical procedures, and has low postoperative complications, and is used to isolate the aortic stent graft during in-situ fenestration and endovascular isolation treatment of the aortic arch while maintaining normal blood flow to the branch vessels, is a technical challenge that urgently needs to be solved. Utility Model Content

[0008] In view of this, the purpose of this utility model is to provide a blood flow maintenance device and an aortic endovascular stent graft system to solve the problems of excessively high requirements for hospital conditions and surgeon skill levels, and high postoperative complication rates in existing endovascular aortic arch repair surgery.

[0009] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows:

[0010] A blood flow maintenance device includes a delivery sheath and a blood flow maintenance basket. The delivery sheath includes a sheath tube, and the blood flow maintenance basket includes a basket, a pusher assembly, and a loading tube. The basket has an extended state that is radially outwardly deployed and a retracted state that is radially inwardly contracted. The pusher assembly is connected to the basket and is used to push the basket within the sheath tube. When the basket is in the extended state after being released outward from the distal opening of the sheath tube, the basket is adapted to support an aortic endovascular stent graft and form an external blood flow channel for the stent graft graft outside the stent graft support.

[0011] Furthermore, the pushing component includes an outer tube, an outer tube handle, a mandrel, and a mandrel handle; the distal end of the outer tube is fixedly connected to the proximal end of the net basket, and the proximal end of the outer tube is connected to the outer tube handle; the mandrel is coaxially inserted into the inner cavity of the outer tube, the distal end of the mandrel is fixedly connected to the distal end of the net basket, and the proximal end of the mandrel passes through the outer tube handle and is connected to the mandrel handle; the mandrel handle drives the distal end of the net basket to move through the mandrel, and the outer tube handle drives the proximal end of the net basket to move through the outer tube; the net basket unfolds or retracts under the control of the mandrel handle and the outer tube handle. Unlike existing technologies that rely solely on self-expansion deformation, this new method utilizes an outer tube handle and a mandrel handle to control the deformation of the mesh basket. This combined approach provides sufficient support when the basket is deployed. Furthermore, during basket retrieval, the outer diameter of the basket can be appropriately reduced by manipulating the handles, facilitating its return to the sheath. This addresses the problems in existing technologies where baskets with high self-expansion support are difficult to retrieve to the sheath or prone to sheath deformation, while baskets with low self-expansion support are easily crushed and deformed by the stent graft, making it difficult to form a stable blood flow channel outside the aortic stent graft and thus affecting blood flow.

[0012] Furthermore, the net basket includes a net basket body, a proximal connecting portion located at the axial proximal end of the net basket body, and a distal connecting portion located at the axial distal end of the net basket body; the net basket is lantern-shaped in the unfolded state, the net basket body is the part with a larger outer diameter in the middle of the net basket in the unfolded state, and the proximal connecting portion and the distal connecting portion are the parts of the net basket that narrow at both ends in the unfolded state; the proximal end of the proximal connecting portion is fixedly connected to the distal end of the outer tube, and the distal end of the distal connecting portion is fixedly connected to the distal end of the mandrel.

[0013] Furthermore, the basket also includes a proximal fixing sleeve and a distal fixing sleeve. The proximal fixing sleeve binds the proximal ends of the proximal connecting portion together, and the distal fixing sleeve binds the distal ends of the distal connecting portion together. The distal end of the outer tube is fixedly connected to the proximal fixing sleeve, and the distal end of the mandrel is fixedly connected to the distal fixing sleeve.

[0014] Furthermore, the pushing component includes a connecting rod and a handle, the distal end of the connecting rod being connected to the proximal end of the net basket, and the proximal end of the connecting rod being connected to the handle; the handle drives the net basket to move within the sheath via the connecting rod.

[0015] Furthermore, the basket is a self-expanding basket, which includes a basket body and a proximal connecting portion located at the axial proximal end of the basket body; the basket body is in the shape of a mesh tube in the unfolded state, and the proximal connecting portion is the part of the basket that narrows at the proximal end in the unfolded state, and the proximal end of the proximal connecting portion is fixedly connected to the distal end of the connecting rod.

[0016] Furthermore, the net basket includes a plurality of small net baskets arranged in sequence and a connecting rod connecting two adjacent small net baskets; the small net baskets are lantern-shaped when unfolded, the distal end of the connecting rod is connected to the axial proximal end of the distal small net basket among two adjacent small net baskets, and the proximal end of the connecting rod is connected to the axial distal end of the proximal small net basket among two adjacent small net baskets; or the net basket is fitted with a plurality of constraint rings in the length direction, the portion of the net basket fitted by the constraint rings is locally narrowed, and the net basket forms a plurality of small net baskets arranged in sequence under the constraint of the constraint rings, the small net baskets being lantern-shaped when unfolded.

[0017] Furthermore, the cross-section of the basket in its unfolded state is circular or elliptical.

[0018] Furthermore, the blood flow maintaining device also includes a loading tube, which is movably sleeved on the outer periphery of the basket in a retracted state, and the loading tube is adapted to be inserted into the proximal opening of the sheath to allow the basket 21 therein to be inserted into the sheath under the action of the pushing component.

[0019] Furthermore, the delivery sheath also includes an expander for expanding the sheath tube, and the pushing component of the blood flow maintaining basket is used to push the basket within the sheath tube and cause the basket to be released outward from the distal opening of the sheath tube and then unfolded from the retracted state to the unfolded state; the sheath tube is adapted to move distally under the action of an external force to retract the unfolded basket back into the sheath tube.

[0020] An aortic endovascular stent graft system includes an aortic endovascular stent graft, a delivery device, a membrane rupture device, and a blood flow maintenance device as described above, used in combination.

[0021] The pushing component is used to push the basket inside the sheath, and the basket is released outward from the distal opening of the sheath and unfolds from the retracted state to the unfolded state.

[0022] The delivery device is used to deliver the aortic endovascular stent graft to one side of the basket in the deployed state, the basket supporting the aortic endovascular stent graft and forming an external blood flow channel for the stent graft on the outside of the supporting aortic endovascular stent graft;

[0023] The sheath is used to retrieve part of the basket before the membrane-breaking device opens the window to make way for the opening position of the membrane-covered stent on the aortic stent.

[0024] The membrane-perforating device is used to open a window at the location to be opened on the aortic endovascular stent graft.

[0025] The sheath is also used to completely retrieve the basket and withdraw one side of the aortic stent graft after the fenestration is completed.

[0026] This utility model's technical solution has the following advantages: During endovascular aortic arch repair, before the release of the aortic stent graft, a pusher component pushes the basket outward from the distal opening of the sheath. After release from the sheath, the basket is in an unfolded state, and its internal cavity forms a blood flow channel. After the aortic stent graft is released, the basket supports one side of the stent graft, forming an external blood flow channel on the outside of the stent graft. Blood can smoothly enter the supra-aortic branch vessels through this external blood flow channel, ensuring blood supply to the head during aortic stent fenestration. This eliminates the time limitation of aortic stent fenestration, making in-situ fenestration for endovascular aortic arch repair simple and widely applicable. This solution has low surgical difficulty and short operation time, facilitating surgical promotion, improving postoperative outcomes, and reducing complications. Attached Figure Description

[0027] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the blood flow maintenance basket inserted into the sheath in Embodiment 1 of this utility model;

[0029] Figure 2 This is a schematic diagram showing the positional relationship between the blood flow maintenance basket and the sheath in the deployed state in Embodiment 1 of this utility model;

[0030] Figure 3 This is a schematic diagram of the structure of the expander expanding the sheath tube in Embodiment 1 of this utility model;

[0031] Figure 4 This is a schematic diagram of the sheath tube in Embodiment 1 of this utility model;

[0032] Figure 5 This is a schematic diagram of the expander in Embodiment 1 of this utility model;

[0033] Figure 6 This is a schematic diagram of the overall structure of the blood flow maintenance basket in Embodiment 1 of this utility model;

[0034] Figure 7 This is a schematic diagram of the blood flow maintenance basket after the loading tube is removed in Embodiment 1 of this utility model;

[0035] Figure 8 This is a schematic diagram of the structure of the basket in Embodiment 1 of this utility model;

[0036] Figure 9 This is a schematic diagram of the structure of the basket constrained inside the loading tube in Embodiment 1 of this utility model;

[0037] Figure 10 This is a schematic diagram showing the positional relationship between the basket, the aortic endovascular stent graft, and the vessel wall in Embodiment 1 of this utility model, wherein the cross-section of the basket is circular;

[0038] Figure 11 This is a schematic diagram showing the positional relationship between the basket, the aortic endovascular stent graft, and the vessel wall in Embodiment 1 of this utility model, wherein the cross-section of the basket is elliptical.

[0039] Figure 12 This is a schematic diagram showing the unfolded shape of the monofilament woven basket in Embodiment 1 of this utility model;

[0040] Figure 13 This is a schematic diagram showing the unfolding of each step in the monofilament spiral winding weaving of the basket in Embodiment 1 of this utility model;

[0041] Figure 14 This is a schematic diagram of the overall structure of the blood flow maintenance basket in Embodiment 2 of this utility model;

[0042] Figure 15 This is a schematic diagram of the blood flow maintenance basket inserted into the sheath in Embodiment 3 of this utility model;

[0043] Figure 16 This is a schematic diagram showing the positional relationship between the blood flow maintenance basket and the sheath in the deployed state in Embodiment 3 of this utility model;

[0044] Figure 17 This is a schematic diagram of the overall structure of the blood flow maintenance basket in Embodiment 3 of this utility model;

[0045] Figure 18 This is a schematic diagram of the blood flow maintenance basket after the loading tube is removed in Embodiment 3 of this utility model;

[0046] Figure 19 This is a schematic diagram of the structure of the basket in Embodiment 3 of this utility model;

[0047] Figure 20This is a schematic diagram of the structure of the basket constrained inside the loading tube in Embodiment 3 of this utility model;

[0048] Figure 21 This is a schematic diagram of the overall structure of the blood flow maintenance basket in Embodiment 4 of this utility model;

[0049] Figure 22 This is a schematic diagram of the overall structure of the blood flow maintenance basket in Embodiment 5 of this utility model;

[0050] Figure 23 This is a schematic diagram of the overall structure of the blood flow maintenance basket in Embodiment Six of this utility model;

[0051] Figure 24 This is a schematic diagram of the overall structure of the blood flow maintenance basket in Embodiment 7 of this utility model;

[0052] Figure 25 A schematic diagram of the thoracic aorta;

[0053] Figure 26 This is a schematic diagram of the blood flow maintenance device basket after it is released at the arterial arch in an embodiment of this utility model;

[0054] Figure 27 This is a schematic diagram showing the relationship between the aortic endovascular stent graft and the blood flow maintenance device after the stent graft is deployed at the aortic arch. The arrows in the diagram indicate the direction of blood flow in the branch vessels.

[0055] Figure 28 A schematic diagram showing the fenestration of the endovascular stent graft on the aortic endovascular stent graft corresponding to the left subclavian artery by the fenestration of the sheath and the unfolded basket at the left clavicle.

[0056] Figure 29 A schematic diagram showing the fenestration of the endovascular stent graft on the aortic endovascular stent graft corresponding to the left common carotid artery by the fenestration device as the sheath is retracted into the basket at the left common carotid artery.

[0057] Figure 30 A diagram showing the basket that extends at the brachiocephalic trunk of the sheath, and the membrane-breaking instrument making a fenestration on the endovascular stent graft corresponding to the brachiocephalic trunk.

[0058] Figure 31 This is a schematic diagram of in-situ fenestration branch reconstruction of the aortic stent graft at the aortic arch location.

[0059] Figure 32 This is a schematic diagram of another implantation method for the blood flow maintenance device of this utility model.

[0060] Explanation of reference numerals in the attached drawings: 11. Sheath; 111. Sheath body; 112. Sheath connector; 113. Side tube; 114. Hemostatic valve; 12. Dilator; 21. Basket; 211. Basket body; 212. Proximal connection; 213. Distal connection; 214. Proximal fixing sleeve; 215. Distal fixing sleeve; 216. Small basket; 217. Connecting rod; 218. Restraint ring; 22. Loading tube; 23. Outer tube; 24. 1. External tube handle; 25. Mandrel; 26. Mandrel handle; 27. Connecting rod; 28. Handle; 3. Aortic endovascular stent graft; 31. Blood flow channel within the endovascular stent graft; 32. Stent window; 4. Blood flow channel outside the endovascular stent graft; 5. Vessel wall; 61. Aortic arch; 62. Descending aorta; 63. Ascending aorta; 64. Brachiocephalic trunk; 65. Left common carotid artery; 66. Right subclavian artery; 7. Membrane rupture device; 8. Branch artery stent. Detailed Implementation

[0061] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0062] Endovascular aortic repair is a minimally invasive endovascular treatment technique that involves inserting a stent through a femoral artery incision to the diseased area of ​​the aorta, repairing the aortic lesion from within the arterial lumen, thus avoiding open surgery. Compared with traditional surgery, endovascular aortic repair significantly reduces surgical trauma, shortens operation time, and reduces surgical complications and mortality.

[0063] In-situ fenestration of the endovascular stent graft is primarily used to treat aortic dissection. When aortic dissection involves the left subclavian artery, left carotid artery, or even the brachiocephalic trunk, doctors perform a fenestration procedure on the endovascular stent graft after implantation to ensure intracranial blood supply. This involves creating a small hole in the endovascular stent graft, passing a guidewire through this hole, and then inserting a balloon to dilate the graft. This creates a cavity (a window) in the endovascular stent graft corresponding to the opening of a branch vessel. A branch artery endovascular stent graft is then placed through this window to maintain communication between the branch vessel and the aorta.

[0064] During in-situ fenestration of the aortic endovascular stent graft (EVS), after the EVS is released within the aortic arch in the chest, the endovascular stent graft covers the supra-arch branch vessels, causing cerebral blood flow interruption before the fenestration reconstruction is complete. This occlusion of the supra-arch branches leads to intracranial ischemia, causing irreversible damage. Prolonged cerebral blood flow interruption can result in loss of consciousness, irreversible brain damage, and even death. The interruption of cerebral blood flow during the fenestration process is a key technical challenge preventing the widespread application of in-situ fenestration methods. Current methods for in-situ fenestration reconstruction of the supra-arch three branches using EVS require cardiopulmonary bypass or deep hypothermic circulatory arrest to address the cerebral blood flow interruption before branch reconstruction. This approach places high demands on hospital facilities and surgeon skill, and also carries a high risk of postoperative complications.

[0065] To address the aforementioned issues, this invention provides a blood flow maintenance device. Before the aortic endovascular stent graft is released to the target location, the blood flow maintenance basket is delivered to the target location via a sheath and then released. The blood flow maintenance basket separates the aortic endovascular stent graft to be fenestrated from the vessel wall on the greater bend side of the target location, forming a blood flow channel on the outside of the aortic endovascular stent graft. This ensures that blood flow in branch vessels is not blocked during the fenestration of the aortic endovascular stent graft, thereby reducing the requirements for hospital conditions and the surgeon's skill level, shortening the operation time, and also helping to reduce postoperative complications, thus facilitating the promotion of the procedure.

[0066] Example 1

[0067] like Figure 1 - Figure 5 The illustrated blood flow maintenance device includes a delivery sheath and a blood flow maintenance basket. The delivery sheath includes a sheath tube 11 and a dilator 12. The sheath tube 11 is used to deliver the blood flow maintenance basket, and the dilator 12 is inserted into the sheath tube 11 from its proximal end to expand the sheath tube 11. The blood flow maintenance basket includes a basket 21, which has an expanded state that is radially outward and a contracted state that is radially inward.

[0068] like Figure 1 and Figure 4As shown, the sheath 11 includes a sheath body 111, a sheath connector 112, a side tube 113, and a hemostatic valve 114. The sheath body 111 is a hollow tube with an internal delivery channel, and it combines flexibility and flexural strength. The distal end of the sheath body 111 is the distal end, the sheath connector 112 is connected to the proximal end of the sheath body 111, the hemostatic valve 114 is located inside the sheath connector 112, and the side tube 113 is connected to the sheath connector 112, with its internal space communicating with the internal space of the sheath body 111. The channel within the sheath body 111 serves as a delivery channel for guidewires, baskets 21, etc. The hemostatic valve 114 can adjust the diameter of its internal valve orifice, allowing guidewires, baskets 21, and smaller tubing components to enter the interior of the sheath body 111 through the hemostatic valve 114. The side tube 113 allows external cleaning fluid to enter the sheath tube body 111 for cleaning the sheath tube 11.

[0069] like Figure 1 and Figure 2 As shown, the blood flow maintenance basket includes a basket 21, a pushing component, and a loading tube 22. The basket 21 is a self-expanding structure, having an expanded state that expands radially outward after the external force is removed and a retracted state that retracts radially inward under external force constraint. The pushing component is connected to the basket 21 and is used to push the basket 21 within the sheath 11. The loading tube 22 is movably fitted around the outer periphery of the basket 21 in the retracted state; the tip of the loading tube 22 can be inserted into the hemostatic valve 114 proximal to the sheath 11.

[0070] like Figure 2 and Figure 4 As shown, before insertion into the sheath 11, the blood flow maintenance basket 21 is confined within the loading tube 22 in a retracted state. When the sheath 11 is inserted, the loading tube 22 is inserted into the hemostatic valve 114 within the sheath connector 112. The loading tube 22 allows the basket 21 within it to smoothly pass through the hemostatic valve 114 into the sheath body 111 under the action of the pushing component. After the basket 21 is pushed to the distal end of the sheath 11, the loading tube 22 can be retracted, and the diameter of the internal valve orifice of the hemostatic valve 114 is reduced to prevent blood leakage through the sheath 11, thus reducing blood loss during the procedure. After being released outward from the opening at the distal end of the sheath 11, the basket 21 expands from a retracted state to an extended state.

[0071] Specifically, the inner diameter of the sheath body 111 is just right for transporting the basket 21. The sheath body 111 can transport and retrieve the basket 21 relatively easily, while ensuring that when the basket 21 is deployed and the sheath body 111 is pushed forward to retrieve it, the opening at the distal end of the sheath body 111 can fit tightly against the basket 21, avoiding damage to blood vessels or displacement of the aortic stent graft during the retrieval process. Before inserting the loading tube 22 into the sheath 11, to ensure that the sheath body 111 can just right for transporting the basket 21, the dilator 12 is inserted into the sheath body 111 of the sheath 11. The dilator 12 expands the sheath body 111, and after the sheath body 111 is fully expanded, it can just right for transporting the basket 21. Then the dilator 12 is withdrawn, and then the loading tube 22 is inserted into the sheath 11.

[0072] Figure 10 This is a schematic diagram showing the positional relationship between the basket 21, the aortic endovascular stent graft 3, and the vessel wall 5, wherein the cross-section of the basket 21 is circular. Figure 11 This diagram illustrates the positional relationship between the basket 21, the aortic endovascular stent graft 3, and the vessel wall 5, where the cross-section of the basket 21 is elliptical. Figure 10 and Figure 11 In the context of the aortic endovascular stent graft 3, the internal channel is the intrastent blood flow channel 31, and the cavities within the basket 21 and the vessel wall 5 not occupied by the basket 21 are the extrastent blood flow channels 4. Figure 10 and Figure 11 It can be seen that the arrangement of the basket 21 inside the vessel wall 5 can form an external blood flow channel 4 for the aortic covered stent 3, thereby allowing blood flow in the vessel to flow through the external blood flow channel 4 into the basket 21 and further into the branch vessels of the aortic arch, maintaining the normal flow of blood in the branch vessels.

[0073] During endovascular aortic arch rupture, the flow maintenance device, aortic endovascular stent graft 3, and rupture device are used in conjunction during the fenestration of the aortic endovascular stent graft. Before the aortic endovascular stent graft 3 is released into the aortic arch, the basket 21 of the flow maintenance device is released on the greater curvature side of the aortic arch. The basket 21 separates the aortic endovascular stent graft 3, which is to be fenestrated, from the vessel wall 5 on the greater curvature side, forming an external blood flow channel 4 for the stent graft, ensuring that blood flow to branch vessels is not blocked during the fenestration of the aortic endovascular stent graft 3. After the rupture device completes the fenestration on the aortic endovascular stent graft 3, the branch artery stent is implanted, and finally the flow maintenance basket is withdrawn, thus achieving apposition of the aortic endovascular stent graft 3 to the aortic arch.

[0074] like Figure 6 and Figure 7As shown, the pushing component includes an outer tube 23, an outer tube handle 24, a spindle 25, and a spindle handle 26. The distal end of the outer tube 23 is fixedly connected to the proximal end of the net basket 21, and the proximal end of the outer tube 23 is connected to the outer tube handle 24. The spindle 25 is coaxially inserted into the inner cavity of the outer tube 23, and the distal end of the spindle 25 is fixedly connected to the distal end of the net basket 21. The proximal end of the spindle 25 passes through the outer tube handle 24 and is connected to the spindle handle 26. The spindle handle 26 drives the distal end of the net basket 21 to move through the spindle 25, and the outer tube handle 24 drives the proximal end of the net basket 21 to move through the outer tube 23. The basket 21, which is fixed at both ends, can be controlled by the spindle handle 26 and the spindle 25 to move the distal end of the basket 21. The outer tube handle 24 and the outer tube 23 control the movement of the proximal end of the basket 21, while the spindle handle 26 and the spindle 25 control the movement of the distal end of the basket 21. The two work together to control the unfolding state of the basket 21, which makes it easy to release the basket 21 in a suitable shape on the large bend side of the target location to be covered by the aortic stent graft 4, and also makes it easy to retrieve the basket 21 later.

[0075] like Figure 7 and Figure 8 As shown, the basket 21 is lantern-shaped when unfolded. The basket 21 includes a basket body 211 in the shape of a mesh tube, a proximal connecting portion 212 located near the axial end of the basket body 211, and a distal connecting portion 213 located far from the axial end of the basket body 211. The basket body 211 is the portion with a larger outer diameter in the middle when the basket 21 is unfolded, while the proximal connecting portion 212 and the distal connecting portion 213 are the portions of the basket 21 that narrow at both ends when unfolded. The proximal end of the proximal connecting portion 212 is fixedly connected to the distal end of the outer tube 23, and the distal end of the distal connecting portion 213 is fixedly connected to the distal end of the mandrel 25. The basket body 211, the proximal connecting portion 212, and the distal connecting portion 213 are an integral structure.

[0076] like Figure 7 and Figure 8As shown, the basket 21 also includes a proximal fixing sleeve 214 fixedly connected to the proximal connecting portion 212 and a distal fixing sleeve 215 fixed to the distal connecting portion 213. The proximal fixing sleeve 213 includes an annular inner steel sleeve and an outer steel sleeve. The proximal connecting portion 212 of the basket 21 is inserted between the inner and outer steel sleeves and fixed to the proximal fixing sleeve 214 by laser welding, brazing, or bonding. The distal fixing sleeve 215 includes a distal steel sleeve. The mandrel 25 passes through the inner steel sleeve of the proximal fixing sleeve 214 and is fixed to the distal connecting portion 213 of the basket 21 by the distal steel sleeve. Specifically, the distal end of the mandrel 25 is inside, the distal connecting portion 213 of the basket 21 is in the middle, and the distal steel sleeve is constrained outside the distal connecting portion 213. The distal end of the mandrel 25, the distal connecting portion 213, and the distal steel sleeve are fixed by brazing, laser welding, or bonding. The far end of the outer tube 23 and the near end fixing sleeve 214 are fixedly connected by laser welding, brazing, bonding and other methods, so as to fix both ends of the basket 21.

[0077] like Figure 7 and Figure 9 As shown, the loading tube 22 is a tubular structure. Before the blood flow maintaining basket is inserted into the sheath, the basket 21 is in a retracted state and constrained within the loading tube 22. Of course, the loading tube 22 can also be designed as a sheath-like structure with a hemostatic valve and side tubes.

[0078] like Figure 7 and Figure 8 As shown, the main body 211, the proximal connecting part 212, and the distal connecting part 213 of the net basket are continuous lantern-shaped structures made of interwoven monofilaments; the net basket 21 is heat-set into its final unfolded form using a tooling fixture. Specifically, as... Figure 12 and Figure 13 As shown, taking a monofilament woven mesh basket as an example, a single metal wire can be wound into a waveform along the posts on the shaping mandrel, then woven once along the tooling, and finally wrapped and fixed with the original metal wire at the overlapping point. A second layer of posts is then wound and connected to the first layer of stent waveform to form a whole. The same method is used to continue winding to form a long strip of woven mesh basket. After the mesh basket 21 is heat-set by the tooling, the posts on the mandrel are removed, and the woven mesh basket is taken off, with the mesh basket heat-set into its final unfolded form. The length variation of this monofilament woven mesh basket 21 in its unfolded state can be controlled within a relatively small range. During and after the fenestration process, the mesh basket 21 can be more smoothly retracted into the sheath without affecting the release position of the aortic endovascular stent graft as much as possible, making the operation relatively simple. Figure 12 and Figure 13 In the diagram, 21a is the starting point of the weaving, 21b is the ending point of the weaving, and 21c is the point where the weaving threads overlap and intertwine.

[0079] This blood flow maintenance device, during endovascular aortic arch repair, uses a pusher assembly to push a basket 21 outward from the distal opening of the sheath 11 before the aortic stent graft is deployed. After deployment, the basket 21 is in an unfolded state, and its internal cavity forms a blood flow channel. After the aortic stent graft 3 is deployed, the basket 21 supports one side of the stent graft 3, forming an external blood flow channel 4 on the outside of the stent graft. Blood can flow smoothly into the supra-aortic branch vessels through this external blood flow channel 4, thus ensuring blood supply to the head during aortic stent graft fenestration. This eliminates the time limitation of aortic stent graft fenestration, making in-situ fenestration for endovascular aortic arch repair surgery simpler and more widely applicable. Using this blood flow maintenance basket reduces the difficulty of endovascular aortic arch repair surgery, shortens the operation time, lowers the requirements for hospital conditions and surgeon skill, and helps reduce postoperative complications, facilitating the widespread adoption of this procedure.

[0080] Example 2

[0081] like Figure 14 The blood flow maintenance device shown differs from Embodiment 1 in that the weaving method of the basket 21 is different. The basket 21 is formed by weaving multiple strands of metal wire into a mesh-like structure, or by laser engraving a basket structure from nickel-titanium tubes. The structure of the pushing component is the same as that of Embodiment 1.

[0082] Example 3

[0083] like Figure 15 - Figure 20 The blood flow maintenance device shown differs from Embodiment 1 in that the structure of the basket 21 and the pushing component are different. The pushing component includes a connecting rod 27 and a handle 28. The distal end of the connecting rod 27 is fixedly connected to the proximal end of the basket 21, and the proximal end of the connecting rod 27 is connected to the handle 28. The handle 28 drives the basket 21 to move within the sheath 11 through the connecting rod 27, and the loading tube 22 is sleeved on the outer periphery of the connecting rod 27. The net basket 21 is a self-expanding net basket, comprising a main body 211 and a proximal connecting portion 212 located at the axial proximal end of the main body 211. In its unfolded state, the main body 211 is tubular in shape, and the proximal connecting portion 212 is the portion of the net basket 21 that narrows proximally in this unfolded state. The distal end of the main body 211 is open, and the distal end of the net basket 21 does not have a distal narrowing portion for closing the distal end of the main body 211. The proximal connecting portion 212 is fixedly connected to the distal end of the connecting rod 27 via a proximal fixing sleeve 214, thus fixing one end of the net basket 21. This proximal-fixed net basket 21 can be operated by a handle 28 and a connecting rod 27, resulting in a simple structure and easy operation.

[0084] Example 4

[0085] like Figure 21 The blood flow maintenance device shown differs from Embodiment 2 in that the weaving method of the basket 21 in the blood flow maintenance basket is different. The basket 21 is a mesh-like structure formed by multiple strands of metal wire, or a basket structure made of nickel-titanium tubes by laser engraving. A proximal fixing sleeve 214 for narrowing the basket 21 is provided at the proximal end of the basket 21, and a distal fixing sleeve 215 for narrowing the basket 21 is provided at the distal end of the basket 21. The proximal fixing sleeve 214 is fixedly connected to the distal end of the connecting rod 27, and the handle 28 drives the basket 21 to move through the connecting rod 27. This basket structure has good stability and is not easily deformed.

[0086] Example 5

[0087] like Figure 22 The blood flow maintenance device shown differs from Embodiment 4 in that the structure of the basket 21 is different. The distal end of the basket 21 is open, and the distal end of the basket 21 does not have a distal narrowing portion for closing the distal end. This basket structure is simple and easy to manufacture.

[0088] Example 6

[0089] like Figure 23 The blood flow maintenance basket shown differs from that in Embodiment 3 in that the structure of the basket 21 is different. The basket 21 includes four small baskets 21 arranged in sequence and a connecting rod 217 connecting two adjacent small baskets 216. The small baskets 216 are lantern-shaped in the deployed state. The distal end of the connecting rod 217 is connected to the proximal axial end of one of the two adjacent small baskets 216 located at the distal end, and the proximal end of the connecting rod 217 is connected to the distal axial end of one of the two adjacent small baskets 216 located at the proximal end. It is understood that the number of small baskets 216 is not limited to four; it can also be three or more. Each fenestration position on the aortic endovascular stent graft 3 corresponds to a branch vessel. When the basket 21 is deployed after being released from the distal opening of the sheath 11, each small basket 216 is supported at one of the fenestration positions on the aortic endovascular stent graft 3 to ensure blood flow supply to the corresponding branch vessel. During the process of retracting the unfolded basket 21 into the sheath 11, multiple small baskets 216 can be sequentially retracted into the sheath 11. This multi-segment basket structure makes the operation easier when retracting a small basket 216, as it is less affected by the pulling force of the rest of the basket 21. This also avoids retracting an excessively long basket at once. Furthermore, adjacent small baskets 216 are more flexible and deformable, better conforming to winding blood vessels.

[0090] Example 7

[0091] like Figure 24 The blood flow maintenance device shown differs from Embodiment Six in that the structure of the basket 21 is different. The basket 21 has three constraint rings 218 fitted along its length. The portion of the basket 21 fitted by the constraint rings 218 is partially narrowed. Under the constraint of the constraint rings 218, the basket 21 forms four sequentially arranged small baskets 216. When unfolded, the small baskets 216 are lantern-shaped, and adjacent small baskets 216 are separated by the constraint rings 218. It is understood that the number of constraint rings 218 on the basket 21 is not limited to three; it can also be two or more. When manufacturing this multi-segment structure of the basket 21, an integral tubular basket can be manufactured first, and then the three constraint rings 218 can be used to narrow the tubular basket at three quarter-nodes along its length to obtain the multi-segment structure. Compared to the net basket in Embodiment Six, this multi-section structure of the net basket 21 not only facilitates the single retrieval of a small net basket 216, avoiding excessive length of the net basket when retrieving it from the sheath, but also simplifies its manufacturing process.

[0092] Example 9

[0093] like Figure 25 - Figure 31 As shown, an aortic endovascular stent graft system includes an aortic endovascular stent graft 3, a delivery device (not shown), a membrane rupture device 7, a branch artery stent 8, and a blood flow maintenance device as described in any of the above embodiments. The sheath 11 of the blood flow maintenance device can be pushed to the distal end of the target location to be covered by the aortic endovascular stent graft. The pushing component of the blood flow maintenance device can push a basket 21 within the sheath 11. The basket 21 is released outward from the distal opening of the sheath 11 and unfolds from a retracted state to an unfolded state. The delivery device is used to deliver the aortic endovascular stent graft 3 to one side of the unfolded basket 21. The basket 21 supports the aortic endovascular stent graft 3 and forms an external blood flow channel 4 on the outside of the aortic endovascular stent graft 3. The membrane rupture device 7 is used to fenestrate the fenestrated position on the aortic endovascular stent graft 3 at the target location to be covered by the delivered aortic endovascular stent graft 3. The branch artery stent 8 is used to be released at the fenestrated position on the aortic endovascular stent graft 3. The sheath 11 is used to retrieve part of the basket 21 before the membrane rupture device 7 opens the window to make way for the fenestration position on the aortic endovascular stent graft 3, and to completely retrieve the basket 21 and withdraw it from the target position to be covered by the aortic endovascular stent graft 3 after the fenestration of the aortic endovascular stent graft 3 is completed.

[0094] Figure 25This is a schematic diagram of the thoracic aorta. The aortic arch 61 is the upper, arched portion of the aorta. Three major arteries emerge from the convex side of the arch, from left to right: the brachiocephalic trunk 64 (innominate artery), the left common carotid artery 65, and the left subclavian artery 66. The anterior end of the aortic arch 61 connects to the ascending aorta 63, and the posterior end connects to the descending aorta 62.

[0095] like Figure 26 - Figure 31 This is a schematic diagram of the in-situ fenestration process of the aortic endovascular stent graft (EVS) in the thoracic aorta. When the target location of the EVS 3 is the aortic arch 61, before the EVS 3 is implanted into the aortic arch 61, the sheath 11 is delivered to the aortic arch 61 via a guidewire. After the distal end of the sheath 11 exceeds the position of the ascending aorta 63 to be covered by the EVS 3, the dilator 12 is inserted into the sheath 11 to dilate it. After the sheath 11 is dilated, the dilator 12 and the guidewire are withdrawn. The basket 21 of the blood flow maintenance device is withdrawn into the loading tube 22, and then the distal end of the loading tube 22 is inserted into the sheath connector 112 at the proximal end of the sheath 11. The pusher component advances the basket 21 until the folded basket 21 is pushed to the distal end of the sheath 11. Then, the sheath 11 is retracted a short distance, allowing the folded basket 21 to unfold outwards from the distal opening of the sheath 11 onto the greater curvature side of the aortic arch 61. The aortic stent graft 3 is then released within the aortic arch 61. Because the unfolded basket 21 is located on the greater curvature side of the aortic arch 61, the aortic stent graft 3 released within the thoracic aortic arch 61 cannot adhere to the vessel wall 5 on the greater curvature side. Blood can flow into the branch vessels of the arch through the interior and periphery of the basket 21, ensuring normal blood supply to the branch vessels during the fenestration of the aortic stent graft 3 and resolving the problem of ischemia at the head of the aortic stent graft 3 during in-situ fenestration.

[0096] After the aortic endovascular stent graft 3 is deployed, a fenestration is performed on the supra-aortic branch from posterior to anterior. The basket 21 is fixed, and the sheath 11 is pushed forward to the anterior edge of the branch vessel to be fenestrated. This ensures a continuous blood flow to the branch to be fenestrated and the preceding branch vessels, while effectively preventing the membrane rupture device 7 from passing through the basket 21 (passing through the basket 21 would cause difficulty in basket retrieval or delay or failure of the fenestration process). After the membrane rupture device 7 penetrates the endovascular graft at the branch, a guidewire is inserted, and then a balloon is advanced along the guidewire to expand the endovascular graft at that location to form a window. After the branch window is fenestrated, a matching branch artery stent 8 can be implanted in the window and the branch vessel to achieve branch vessel reconstruction, or the branch vessels can be reconstructed by using the branch artery stent 8 after fenestration is completed at the openings of all branch vessels. Secure the basket 21 and continue advancing the sheath 11 until the distal end of the basket 21 is retracted into the sheath 11, reaching the anterior edge of the next branch vessel to be fenestrated. This ensures blood flow to the branch vessel to be fenestrated, while also maintaining sufficient blood flow to branches that have already been fenestrated or reconstructed. Perform fenestration on the previous branch vessel in the same manner. After all branch vessels have been fenestrated, secure the basket 21 and slowly continue advancing the sheath 11 until the basket 21 is completely retracted into the sheath 11. Withdraw the sheath 11, ensuring complete adhesion between the aortic stent graft 3 and the vessel wall 5.

[0097] Specifically, after the aortic stent graft 3 is fully deployed, the preferred sequence for fenestration of the supra-aortic branches is from posterior to anterior. When fenestrating a specific branch vessel, the sheath 11 is advanced and the basket 21 posterior to that branch vessel is drawn into the sheath 11. After fenestration, the basket 21 is retrieved, and the branch stent is then inserted to achieve branch vessel reconstruction. This eliminates the time limitation of aortic arch fenestration, making in-situ fenestration for endovascular aortic arch lesion repair simple and widely applicable; it also improves postoperative outcomes and reduces surgical complications. This invention primarily addresses the problem in endovascular aortic arch reconstruction surgery where in-situ fenestration of branch vessels requires cardiopulmonary bypass or deep hypothermic circulatory arrest to address cerebral ischemia, resulting in high surgical difficulty and a high complication rate. It simplifies and facilitates in-situ fenestration for endovascular aortic arch lesions.

[0098] Example 10

[0099] like Figure 32 The aortic endovascular stent graft system shown differs from Embodiment 9 in that it further includes two bypass sheaths 9 and a connecting tube 91.

[0100] The bypass sheath 9 is specifically a sheath with a size of 10F-16F. The difference between the bypass sheath 9 and a conventional vascular sheath lies in the inner diameter of its side tubes. The inner diameter of the side tubes and the valve of the bypass sheath 9 are close to or larger than the inner diameter of the sheath, enabling bypass function through the side tubes. Simultaneously, the hemostatic valve has a leak-proof function when used with multiple instruments. The connecting tube 91 is used to connect the side tubes of the two bypass sheaths inserted into the left and right carotid arteries. The inner diameter of the connecting tube 91 is close to or larger than the inner diameter of the bypass sheaths, ensuring bypass flow. This aortic endovascular stent graft system can be used for double fenestration (fenestration of the left common carotid artery and the left subclavian artery) or triple fenestration.

[0101] During double fenestration surgery, a flow maintenance device can be used in combination with a standard 8-10F vascular sheath or with a bypass sheath 9. Before implantation of the aortic endovascular stent graft, the bypass sheath 9 is inserted into the left common carotid artery, with its tip reaching the opening of the branch vessel. A flow maintenance basket is then advanced from within the bypass sheath 9 until its tip just exceeds the opening of the bypass sheath 9. A fenestration of the left subclavian artery is then established. After preparation, the aortic endovascular stent graft is released to the intended position. The sheath of the flow maintenance device is then withdrawn outside the sheath of the vascular sheath, and the basket unfolds automatically. A space for blood flow is created lateral to the aortic endovascular stent graft. A puncture needle is inserted through the sheath of the vascular sheath to penetrate the endovascular stent graft. After inserting a guidewire, a balloon is advanced along the guidewire to dilate and achieve in-situ fenestration of the left carotid artery. The sheath of the flow maintenance device is then inserted, and the sheath is advanced back into the basket within the sheath. Finally, the entire device is withdrawn from the vascular sheath. Then, a fenestration was performed on the left subclavian artery, and the left common carotid artery and left subclavian artery were reconstructed using branch artery stents.

[0102] During the three-fenestration procedure, bypass sheaths 9 are inserted through punctures in the left and right common carotid arteries, with the tip of the bypass sheath 9 extending to the opening of the branch vessel. A flow maintenance device is then inserted through the right common carotid artery until the end of the basket just exceeds the sheath opening of the bypass sheath 9. A fenestration approach is then established in the left subclavian artery. Connecting tube 91 is then connected to the side tubes of the two bypass sheaths 9, and air is released. The aortic stent graft is released to the intended position, and the sheath of the flow maintenance device is withdrawn to the outside of the sheath of the vascular sheath assembly. The basket 21 then deploys automatically. A space for blood flow is formed lateral to the aortic stent graft in the ascending aorta. Blood flows through this space into the brachiocephalic trunk and exits from the bypass sheath 9 in the right common carotid artery. Through the connection 91, blood flows into the bypass sheath 9 in the left common carotid artery and then into the left carotid artery. Next, a puncture needle is inserted through the shunt sheath 9 of the left common carotid artery to penetrate the endovascular membrane. A guidewire is then inserted, followed by balloon dilation along the guidewire to achieve in-situ fenestration of the left common carotid artery. Then, a puncture needle is inserted through the shunt sheath 9 of the right common carotid artery to penetrate the endovascular membrane. A guidewire is then inserted, followed by balloon dilation along the guidewire to achieve in-situ fenestration of the brachiocephalic trunk. Next, the flow maintenance device sheath is inserted into the shunt sheath 9 of the right common carotid artery. The flow maintenance device sheath is then advanced and retracted into the basket within the sheath, and then withdrawn entirely from the vascular sheath. Finally, a fenestration is performed on the left subclavian artery, and reconstruction of the brachiocephalic trunk, left common carotid artery, and left subclavian artery is completed using a peripheral vascular stent graft.

[0103] This method of fenestration for aortic endovascular stent grafts includes the following steps:

[0104] Step S1: Before implanting the aortic endovascular stent graft 3 at the target location, advance the distal end of the sheath 11 to the target location covered by the aortic endovascular stent graft 3.

[0105] Step S2: Push the folded basket 21 to the far end of the sheath 11, pull the sheath 11 back a distance, and the basket 21 will expand outward from the opening at the far end of the sheath 11 and unfold on the large bend side of the target position.

[0106] Step S3: Implant the aortic endovascular stent graft 3 at the target location, with the unfolded basket 21 positioned between the aortic endovascular stent graft 3 and the greater curvature of the target location;

[0107] Step S4: Push the sheath 11 one distance, and the basket 21, which is in the unfolded state, is partially retracted and returned to the sheath 11, making way for the fenestration position corresponding to the large bend side of the aortic endovascular stent graft 3 and the target position.

[0108] Step S5: Insert the membrane-perforating device 7 into the fenestration position of the aortic endovascular stent graft 3. The membrane-perforating device 7 creates a fenestration on the endovascular stent graft 3, forming a stent window 32 on the endovascular stent graft. Repeat steps S5 and S6 three times until three stent windows 32 are formed on the endovascular stent graft.

[0109] Step S6: After the three stent windows 32 on the aortic endovascular stent graft 3 are opened, the sheath 11 is advanced, and the basket 21 in the unfolded state is completely retracted into the sheath 11. The sheath 11 is then withdrawn from the target position covered by the aortic endovascular stent graft 3.

[0110] Step S7: Insert a matching branch artery stent 8 into the branch vessel through the three stent windows 32 to achieve branch vessel reconstruction.

[0111] The key to the fenestration method for aortic endovascular stent grafts is to first release the basket 21, which separates the aortic endovascular stent graft 3 to be fenestrated from the vessel wall 5 on the greater curvature side, so that blood flow can be continuously supplied to the supra-arch branch vessels during the fenestration process, ensuring that the branch blood flow is not interrupted during the fenestration process.

[0112] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A blood flow maintenance device, characterized in that, The device includes a delivery sheath and a blood flow maintenance basket. The delivery sheath includes a sheath tube (11), and the blood flow maintenance basket includes a basket (21) and a pusher assembly. The basket (21) has an extended state that is radially outward and a retracted state that is radially inward. The pusher assembly is connected to the basket (21) and is used to push the basket (21) within the sheath tube (11). When the basket (21) is in the extended state after being released outward from the distal opening of the sheath tube (11), the basket (21) is adapted to support the aortic endovascular stent graft (3) and form an external blood flow channel (4) for the endovascular stent graft (3) on the outside of the supporting aortic endovascular stent graft (3).

2. The blood flow maintaining device according to claim 1, characterized in that, The pushing component includes an outer tube (23), an outer tube handle (24), a spindle (25), and a spindle handle (26); the distal end of the outer tube (23) is fixedly connected to the proximal end of the net basket (21), and the proximal end of the outer tube (23) is connected to the outer tube handle (24); the spindle (25) is coaxially inserted into the inner cavity of the outer tube (23), the distal end of the spindle (25) is fixedly connected to the distal end of the net basket (21), and the proximal end of the spindle (25) passes through the outer tube handle (24) and is connected to the spindle handle (26); the spindle handle (26) drives the distal end of the net basket (21) to move through the spindle (25), and the outer tube handle (24) drives the proximal end of the net basket (21) to move through the outer tube (23); the net basket (21) unfolds or retracts under the control of the spindle handle (26) and the outer tube handle (24).

3. The blood flow maintaining device according to claim 2, characterized in that, The basket (21) includes a basket body (211), a proximal connecting part (212) located at the proximal end of the axial direction of the basket body (211), and a distal connecting part (213) located at the distal end of the axial direction of the basket body (211). The basket (21) is lantern-shaped when unfolded. The basket body (211) is the part with a larger outer diameter in the middle when unfolded. The proximal connecting part (212) and the distal connecting part (213) are the parts of the basket (21) that are narrowed at both ends when unfolded. The proximal end of the proximal connecting part (212) is fixedly connected to the distal end of the outer tube (23), and the distal end of the distal connecting part (213) is fixedly connected to the distal end of the spindle (25).

4. The blood flow maintaining device according to claim 1, characterized in that, The pushing component includes a connecting rod (27) and a handle (28). The distal end of the connecting rod (27) is connected to the proximal end of the net basket (21), and the proximal end of the connecting rod (27) is connected to the handle (28). The handle (28) drives the net basket (21) to move inside the sheath (11) through the connecting rod (27).

5. The blood flow maintaining device according to claim 4, characterized in that, The basket (21) is a self-expanding basket. The basket (21) includes a basket body (211) and a proximal connecting part (212) located at the axial proximal end of the basket body (211). The basket body (211) is in the shape of a mesh tube when unfolded. The proximal connecting part (212) is the part of the basket (21) that narrows at the proximal end when unfolded. The proximal end of the proximal connecting part (212) is fixedly connected to the distal end of the connecting rod (27).

6. The blood flow maintaining device according to claim 4, characterized in that, The net basket (21) includes a plurality of small net baskets (216) arranged in sequence and a connecting rod (217) connecting two adjacent small net baskets (216); the small net baskets (216) are lantern-shaped when unfolded, the distal end of the connecting rod (217) is connected to the axial proximal end of one of the two adjacent small net baskets (216) located at the distal end, and the proximal end of the connecting rod (217) is connected to the axial distal end of one of the two adjacent small net baskets (216) located at the proximal end; or the net basket (21) is fitted with a plurality of constraint rings (218) in the length direction, the part of the net basket (21) fitted by the constraint rings (218) is locally narrowed, and the net basket (21) forms a plurality of small net baskets (216) arranged in sequence under the constraint of the constraint rings, and the small net baskets (216) are lantern-shaped when unfolded.

7. The blood flow maintaining device according to any one of claims 1-6, characterized in that, The blood flow maintenance device further includes a loading tube (22) which is movably sleeved on the periphery of the basket (21) in a retracted state, and the loading tube (22) is adapted to be inserted into the proximal opening of the sheath (11) to allow the basket (21) therein to be inserted into the sheath (11) under the action of the pushing component.

8. The blood flow maintaining device according to claim 7, characterized in that, The delivery sheath also includes an expander (12) for expanding the sheath tube (11); the pushing component is used to push the basket (21) inside the sheath tube (11) and cause the basket (21) to be released outward from the distal opening of the sheath tube (11) and unfolded from the retracted state to the unfolded state; the sheath tube (11) is adapted to move distally under the action of external force to retract the basket (21) in the unfolded state into the sheath tube (11).

9. An aortic endovascular stent graft system, characterized in that, It includes an aortic endovascular stent graft (3) used in combination, a delivery device, a membrane rupture device (7), and a blood flow maintenance device as described in any one of claims 1-8 above; The pushing component is used to push the basket (21) inside the sheath (11), and the basket (21) is released outward from the distal opening of the sheath (11) and unfolded from the retracted state to the unfolded state; The delivery device is used to deliver the aortic endovascular stent graft (3) to one side of the basket (21) in the deployed state, the basket (21) supports the aortic endovascular stent graft (3) and forms an external blood flow channel (4) for the endovascular stent graft on the outside of the supporting aortic endovascular stent graft (3); The sheath (11) is used to retrieve part of the basket (21) before the membrane rupture device opens the window to make way for the window opening position on the aortic endovascular stent graft (3); The membrane-breaking device (7) is used to open a window at the fenestration site on the aortic endovascular stent graft (3); The sheath (11) is also used to completely retrieve the basket (21) and withdraw it from one side of the aortic stent graft (3) after the fenestration is completed.

Images