Blood flow maintaining device, aorta covered stent system and windowing method of aorta covered stent

Abstract

The invention discloses a blood flow maintaining device, an aorta covered stent system and a windowing method of an aorta covered stent, 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] The present invention relates to the technical field of interventional medical devices, and particularly relates to a blood flow maintenance device for supra-aortic branch vessels, an aortic covered stent system, and a windowing method for an aortic covered stent. Background Art

[0002] With the aging of the population and the increase in hypertension and arteriosclerosis, the number of patients with aortic diseases has been increasing year by year. For example, type A dissection involving arch lesions accounts for 70% of aortic dissections. Currently, open surgery is still the main treatment for this part of patients. However, open surgery has large trauma, requires extracorporeal circulation or even deep hypothermic circulatory arrest, and has a long operation time. The longer the operation time, the higher the incidence of postoperative complications and mortality. The minimally invasive treatment of diseases involving the aortic arch is a new treatment method for aortic diseases. Currently, the minimally invasive treatment of aortic arch diseases generally adopts the three-branch (multi-branch) endovascular reconstruction technology of the aortic arch.

[0003] Currently, the endovascular exclusion technology is mainly used for the treatment of non-major branch vessel segments such as the descending aorta and branch vessels with no strict requirements for operation time and blood flow interruption, such as the thoracoabdominal aorta and the abdominal aorta-iliac artery. There are three important branch vessels above the aortic arch, which are responsible for supplying blood to the brain and upper limbs. The blood supply interruption time to the brain cannot be too long. Generally, ischemia for more than five minutes will cause severe irreversible damage to the brain due to hypoxia, and even lead to the death of the patient. The branch vessels above the aortic arch vary in the number, diameter, spacing, position, and direction of the branches from person to person, without obvious regularity. These factors determine that the use of multi-branch covered stents and the design of endovascular exclusion treatment for the aortic arch are difficult to meet the clinical needs, because the required number of branch stent specifications is too large, the operation difficulty is high, the surgical complications are high, it is easy to block the branch blood flow, and the branches are easy to occlude.

[0004] Adopting the method of inlaying branch combinations, although it reduces the required number of stent specifications and has a certain commercial feasibility, it still faces problems such as complex surgical operations, intraoperative ischemia, high requirements for operation skills, high complications, and difficulty in popularizing this surgical method in general hospitals. At the same time, the method of reconstructing branch vessels by inlaying branches changes the opening position of the branch vessels, which hinders the subsequent minimally invasive interventional treatment of branch vessels. There is also the problem that the deviation between the inlaid branch and the direction of the vascular branch is too large to reconstruct the branch.

[0005] Performing in-situ windowing or corresponding small windowing on the aortic covered stent according to the branch position outside the body can well solve the problems of differences in the number, diameter, spacing, position, and direction of the branch vessel stents. Moreover, the required number of branch vessel stents is small, and the branch entrance is consistent with the original branch vessel entrance, which will not affect the long-term minimally invasive interventional requirements of the branch vessels.

[0006] Although in situ fenestration has many advantages and is suitable for full reconstruction across the arch, during the existing in situ fenestration for intraluminal isolation treatment of the aortic arch full branches, after the aortic stent graft is released in the thoracic aortic arch, the aortic stent graft membrane blocks the branch vessels on the arch, which will cause interruption of cerebral blood flow before the fenestration reconstruction is completed. After the membrane blocks the branches on the arch, it will cause intracranial ischemia, leading to irreversible damage. Interruption of cerebral blood flow for 5 minutes will cause the human body to lose consciousness, cause irreversible damage to the brain, and even lead to the death of the patient. The aortic stent graft will block the brain during the fenestration process, which is a technical problem that the in situ fenestration method cannot be widely promoted and applied. In the existing in situ fenestration reconstruction of the full branches on the arch, the method of extracorporeal circulation or deep hypothermic circulatory arrest is required to solve the problem of head blood flow being blocked by the aortic stent graft before branch reconstruction (extracorporeal circulation allows the brain blood flow to be supplied externally during the fenestration reconstruction process to avoid cerebral ischemia; deep hypothermic circulatory arrest is to use deep hypothermic conditions to prolong the time of death due to ischemia in the brain). Both extracorporeal circulation and deep hypothermic circulatory arrest technology have very high requirements on hospital conditions and surgeon skills, and also bring the problem of high complications.

[0007] Therefore, how to design a blood flow maintenance device with low surgical difficulty, conducive to surgical promotion and low postoperative complications, to isolate the aortic stent graft during the in situ fenestration and intracavitary isolation treatment of the aortic arch and maintain normal blood flow supply to the branch vessels is a technical problem that urgently needs to be solved. Summary of the invention

[0008] In view of this, the purpose of the present invention is to provide a blood flow maintaining device, an aortic stent graft system and a window opening method of an aortic stent graft, so as to solve the problems of existing aortic arch intracavitary isolation treatment surgery having too high requirements on hospital conditions and surgeon level and high postoperative complications.

[0009] In order to solve the above technical problems, the technical solution of the present invention is as follows:

[0010] A blood flow maintaining device comprises a delivery sheath and a blood flow maintaining basket, wherein the delivery sheath comprises a sheath tube, and the blood flow maintaining basket comprises a basket, a pushing assembly and a loading tube; the basket has an expanded state in which it is expanded radially outward and a collapsed state in which it is collapsed radially inward; the pushing assembly is connected to the basket, and the pushing assembly is used to push the basket in the sheath tube; when the basket is in the expanded state after being released outward from the distal end opening of the sheath tube, the basket is suitable for supporting an aortic stent graft and forming a stent graft blood flow channel outside the stent graft on the outside of the supported aortic stent graft.

[0011] Further, 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 basket, and the proximal end of the outer tube is connected to the outer tube handle; the mandrel is coaxially disposed in the inner cavity of the outer tube, the distal end of the mandrel is fixedly connected to the distal end of the 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 basket to move through the mandrel, and the outer tube handle drives the proximal end of the basket to move through the outer tube; the basket unfolds or folds under the control of the mandrel handle and the outer tube handle. Using the outer tube handle and the mandrel handle to control the deformation of the basket is different from the basket that only relies on self-expansion deformation in the prior art. The way of using the outer tube handle and the mandrel handle to cooperate to control the deformation of the basket can, on the one hand, provide sufficient supporting force when the basket is in the unfolded state; on the other hand, when recovering the basket, the outer diameter of the basket can be appropriately reduced by controlling the outer tube handle and the mandrel handle, which is convenient for recovering the basket into the sheath; it solves the problems in the prior art that the basket with large self-expansion supporting force is not easy to be recovered into the sheath or is likely to cause the deformation of the sheath, and the basket with small self-expansion supporting force is easily collapsed and deformed by the covered stent, making it difficult to form a stable blood flow channel outside the aortic covered stent, thus affecting blood flow.

[0012] Further, the basket includes a basket main body, a proximal connecting portion located at the axial proximal end of the basket main body, and a distal connecting portion located at the axial distal end of the basket main body; the basket is in a lantern shape in the unfolded state, the basket main body is the part with a larger middle outer diameter when the basket is in the unfolded state, and the proximal connecting portion and the distal connecting portion are the parts with narrowed ends when the basket is 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] Further, the basket further includes a proximal fixing sleeve and a distal fixing sleeve, the proximal fixing sleeve constrains the proximal ends of the proximal connecting portions together, and the distal fixing sleeve constrains the distal ends of the distal connecting portions 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] Further, the pushing component includes a connecting rod and a handle, the distal end of the connecting rod is connected to the proximal end of the basket, and the proximal end of the connecting rod is connected to the handle; the handle drives the basket to move in the sheath through the connecting rod.

[0015] Furthermore, the basket is a self-expanding basket, comprising a basket body and a proximal connecting portion located at the axial proximal end of the basket body; the basket body is in a net tube shape in an expanded state, the proximal connecting portion is a portion of the basket that is narrowed at the proximal end in the expanded state, and the proximal end of the proximal connecting portion is fixedly connected to the distal end of the connecting rod.

[0016] Further, the mesh basket includes a plurality of small mesh baskets arranged in sequence and a connecting rod connected between two adjacent small mesh baskets; the small mesh basket is lantern-shaped in the expanded state, the distal end of the connecting rod is connected to the axial proximal end of a small mesh basket located at the distal end of the two adjacent small mesh baskets, and the proximal end of the connecting rod is connected to the axial distal end of a small mesh basket located at the proximal end of the two adjacent small mesh baskets; or the mesh basket is sleeved with a plurality of constraint rings in the length direction, the part of the mesh basket sleeved by the constraint ring is locally narrowed, and the mesh basket forms a plurality of small mesh baskets arranged in sequence under the constraint of the constraint ring, and the small mesh basket is lantern-shaped in the expanded state.

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

[0018] Furthermore, the blood flow maintaining device also includes a loading tube, which is movably mounted on the outer periphery of the mesh basket in a folded state, and is suitable for being inserted into the proximal opening of the sheath tube to allow the mesh basket 21 therein to be inserted into the sheath tube under the action of the pushing assembly.

[0019] Furthermore, the delivery sheath also includes an expander for expanding the sheath tube, and the pushing assembly of the blood flow maintaining basket is used to push the basket in the sheath tube, and to make the basket expand from the collapsed state to the expanded state after being released outward from the distal opening of the sheath tube; the sheath tube is suitable for moving distally under the action of external pushing force to collapse the basket in the expanded state and then recover it into the sheath tube.

[0020] An aortic stent graft system, comprising an aortic stent graft, a delivery device, a membrane rupture device and the blood flow maintenance device as described above, which are used in combination;

[0021] The pushing assembly is used to push the net basket in the sheath tube, and the net basket is released outward from the distal end opening of the sheath tube and then expanded from the retracted state to the expanded state;

[0022] The delivery device is used to deliver the aortic stent graft to one side of the basket in the expanded state, the basket supports the aortic stent graft and forms a stent graft outer blood flow channel on the outer side of the supported aortic stent graft;

[0023] The sheath is used to recover part of the basket before windowing the membrane-breaking device to avoid the position to be windowed on the membrane of the aortic covered stent;

[0024] The membrane-breaking device is used to make a window at the position to be windowed on the membrane of the aortic covered stent;

[0025] The sheath is also used to completely recover the basket and withdraw from one side of the aortic covered stent after the windowing of the aortic covered stent is completed.

[0026] A method for windowing an aortic covered stent, comprising the following steps:

[0027] S1. Before the aortic covered stent is implanted at the target position to be covered, advance the distal end of the sheath to the distal end of the target position to be covered by the aortic covered stent;

[0028] S2. Advance the basket in the retracted state to the distal end of the sheath, withdraw the sheath by a certain distance, and the basket is released outward from the distal opening of the sheath and then unfolds on the major curvature side of the target position to be covered by the aortic covered stent;

[0029] S3. Implant the aortic covered stent at the target position to be covered by the aortic covered stent, and the unfolded basket supports between the aortic covered stent and the major curvature side of the target position to be covered by the aortic covered stent;

[0030] S4. Advance the sheath by a certain distance, and part of the unfolded basket is retracted and recovered into the sheath to avoid the position to be windowed on the membrane of the aortic covered stent;

[0031] S5. Implant the membrane-breaking device at the position to be windowed on the membrane of the aortic covered stent, and the membrane-breaking device makes a window at the position to be windowed on the membrane of the aortic covered stent;

[0032] S6. After the windowing at the position to be windowed on the membrane of the aortic covered stent is completed, advance the sheath, and the unfolded basket is completely recovered into the sheath, and then withdraw the sheath from the target position to be covered by the aortic covered stent.

[0033] The technical solution of the present invention has the following advantages: During the endovascular exclusion treatment of the aortic arch, before the release of the aortic covered stent, the basket is first pushed outwards from the distal opening of the sheath by using the pushing component. The basket after being released from the sheath is in an unfolded state, and the internal cavity of the basket can form a blood flow channel. After the release of the aortic covered stent, the basket will support on one side of the aortic covered stent and form an extracorporeal covered stent blood flow channel outside the supported aortic covered stent. Blood can smoothly enter the supra-aortic branch vessels through the extracorporeal covered stent blood flow channel, ensuring blood supply to the head during the windowing process of the aortic covered stent. Thus, the limitation of the windowing time of the aortic covered stent is eliminated, making the in-situ windowing for endovascular exclusion diagnosis and treatment of the aortic arch simple and popularizable. This solution has a low surgical difficulty, a short surgical time, is conducive to the popularization of the surgery, improves the postoperative effect, and reduces complications. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0035] Figure 1 Structural schematic diagram of the blood flow maintenance basket inserted into the sheath in Embodiment 1 of the present invention;

[0036] Figure 2 Schematic diagram of the positional relationship between the unfolded basket of the blood flow maintenance basket and the sheath in Embodiment 1 of the present invention;

[0037] Figure 3 Structural schematic diagram when the dilator expands the sheath in Embodiment 1 of the present invention;

[0038] Figure 4 Structural schematic diagram of the sheath in Embodiment 1 of the present invention;

[0039] Figure 5 Structural schematic diagram of the dilator in Embodiment 1 of the present invention;

[0040] Figure 6 Overall structural schematic diagram of the blood flow maintenance basket in Embodiment 1 of the present invention;

[0041] Figure 7 Structural schematic diagram of the blood flow maintenance basket after removing the loading tube in Embodiment 1 of the present invention;

[0042] Figure 8 Structural schematic diagram of the basket in Embodiment 1 of the present invention;

[0043] Figure 9Schematic structural diagram of the mesh basket constrained within the loading tube in the first embodiment of the present invention;

[0044] Figure 10 Schematic position relationship diagram of the mesh basket, aortic covered stent, and blood vessel wall in the first embodiment of the present invention, wherein the cross-section of the mesh basket is circular;

[0045] Figure 11 Schematic position relationship diagram of the mesh basket, aortic covered stent, and blood vessel wall in the first embodiment of the present invention, wherein the cross-section of the mesh basket is oval;

[0046] Figure 12 Schematic deployment diagram of the single-wire woven mesh basket in the first embodiment of the present invention;

[0047] Figure 13 Schematic deployment diagram of each step of the single-wire spiral-wound woven mesh basket in the first embodiment of the present invention;

[0048] Figure 14 Schematic overall structure diagram of the blood flow maintenance mesh basket in the second embodiment of the present invention;

[0049] Figure 15 Schematic structural diagram of the blood flow maintenance mesh basket inserted into the sheath tube in the third embodiment of the present invention;

[0050] Figure 16 Schematic position relationship diagram of the mesh basket of the blood flow maintenance mesh basket and the sheath tube in the deployed state in the third embodiment of the present invention;

[0051] Figure 17 Schematic overall structure diagram of the blood flow maintenance mesh basket in the third embodiment of the present invention;

[0052] Figure 18 Schematic structural diagram of the blood flow maintenance mesh basket after removing the loading tube in the third embodiment of the present invention;

[0053] Figure 19 Schematic structural diagram of the mesh basket in the third embodiment of the present invention;

[0054] Figure 20 Schematic structural diagram of the mesh basket constrained within the loading tube in the third embodiment of the present invention;

[0055] Figure 21 Schematic overall structure diagram of the blood flow maintenance mesh basket in the fourth embodiment of the present invention;

[0056] Figure 22 Schematic overall structure diagram of the blood flow maintenance mesh basket in the fifth embodiment of the present invention;

[0057] Figure 23 Schematic overall structure diagram of the blood flow maintenance mesh basket in the sixth embodiment of the present invention;

[0058] Figure 24 Schematic diagram of the overall structure of the blood flow maintenance basket in the seventh embodiment of the present invention;

[0059] Figure 25 Schematic diagram of the thoracic aorta;

[0060] Figure 26 Schematic diagram of the basket of the blood flow maintenance device in the present invention after being released at the aortic arch;

[0061] Figure 27 Schematic diagram of the relationship between the aortic covered stent and the blood flow maintenance device after being released at the aortic arch. The arrow in the figure indicates the blood flow direction of the branch blood vessel;

[0062] Figure 28 Schematic diagram of the basket deployed when the sheath is retracted at the left clavicle, and the membrane puncturing instrument makes a window in the membrane of the aortic covered stent corresponding to the left subclavian artery;

[0063] Figure 29 Schematic diagram of the basket deployed when the sheath is retracted at the left common carotid artery, and the membrane puncturing instrument makes a window in the membrane of the aortic covered stent corresponding to the left common carotid artery;

[0064] Figure 30 Schematic diagram of the basket deployed when the sheath is retracted at the brachiocephalic trunk, and the membrane puncturing instrument makes a window in the membrane of the aortic covered stent corresponding to the brachiocephalic trunk;

[0065] Figure 31 Schematic diagram after in-situ fenestration and branch reconstruction of the aortic covered stent at the aortic arch;

[0066] Figure 32 Schematic diagram of another implantation method of the blood flow maintenance device of the present invention.

[0067] Explanation of reference numerals: 11. Sheath; 111. Sheath body; 112. Sheath joint; 113. Side tube; 114. Hemostatic valve; 12. Dilator; 21. Basket; 211. Basket main body; 212. Proximal connecting part; 213. Distal connecting part; 214. Proximal fixing sleeve; 215. Distal fixing sleeve; 216. Small basket; 217. Link; 218. Constraint ring; 22. Loading tube; 23. Outer tube; 24. Outer tube handle; 25. Mandrel; 26. Mandrel handle; 27. Connecting rod; 28. Handle; 3. Aortic covered stent; 31. Blood flow channel inside the covered stent; 32. Stent window; 4. Blood flow channel outside the covered stent; 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 puncturing instrument; 8. Branch artery stent. Detailed implementation manners

[0068] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0069] Endovascular aortic repair is a minimally invasive endovascular treatment technique. Through an incision in the femoral artery, a stent is sent to the diseased part of the aorta, and the aortic lesion is repaired from within the artery, thus avoiding open surgery. Compared with traditional surgical operations, endovascular aortic repair greatly reduces the trauma of surgery, significantly shortens the operation time, and reduces surgical complications and mortality.

[0070] In-situ fenestration of aortic covered stents is mainly used for the treatment of aortic dissection. When aortic dissection involves the left subclavian artery, left carotid artery or even the brachiocephalic trunk, in order to ensure intracranial blood supply after the implantation of an aortic covered stent, doctors will perform a fenestration operation on the covered stent in the body after the implantation of the aortic covered stent. That is, a small hole is first made in the covering of the aortic covered stent, then a guide wire is passed through the small hole through the covering, and then a balloon is sent to dilate the place. A hole corresponding to the opening position of the branch vessel, that is, a window, is formed in the covering, and then a branch artery covered stent is placed through the window to maintain the connection between the branch vessel and the aorta.

[0071] During in-situ fenestration of aortic covered stents, after the aortic covered stent is released in the thoracic aortic arch, the covering of the aortic covered stent blocks the branch vessels on the arch, and cerebral blood flow interruption will occur before the completion of fenestration reconstruction. Blocking the branch vessels on the arch by the covering will cause intracranial ischemia, leading to irreversible damage. A long cerebral blood flow time will cause the body to lose consciousness, cause irreversible damage to the brain, and even lead to the death of the patient. The fact that the in-situ fenestration method of aortic covered stents will block cerebral blood supply during the fenestration process is a technical problem that prevents the in-situ fenestration method from being widely promoted and applied. The existing methods for in-situ fenestration and reconstruction of the three branch vessels on the arch of aortic covered stents need to use extracorporeal circulation or deep hypothermic circulatory arrest to solve the problem that cerebral blood flow is blocked by the aortic covered stent before branch reconstruction. This solution has too high requirements for hospital conditions and the level of operators, and there are also problems of relatively high postoperative complications.

[0072] To solve the above problems, the present invention provides a blood flow maintaining device. Before the aortic stent graft is released to the target position to be covered, the blood flow maintaining basket is transported to the target position through a sheath and then released. The blood flow maintaining basket separates the aortic stent graft to be fenestrated from the tube wall on the greater curvature side of the target position to be covered, forming a blood flow channel outside the aortic stent graft, ensuring that the blood flow of the branch vessels is not blocked during the fenestration of the aortic stent graft; thereby reducing the requirements on hospital conditions and the operator's operating level, shortening the operation time, and at the same time helping to reduce postoperative complications and facilitate the promotion of surgery.

[0073] Embodiment 1

[0074] like Figure 1 - Figure 5 A blood flow maintenance device shown 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. The dilator 12 is used to be inserted into the sheath tube 11 from the proximal end of the sheath tube 11 to expand the sheath tube 11. The blood flow maintenance basket includes a basket 21, which has an expanded state of radially expanding outward and a collapsed state of radially contracting inward.

[0075] like Figure 1 and Figure 4 As 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 a delivery channel inside, and the sheath body 111 has both flexibility and anti-bending properties; the distal end of the sheath body 111 is the distal end of the sheath body 111, the sheath connector 112 is connected to the proximal end of the sheath body 111, the hemostatic valve 114 is arranged in the sheath connector 112, the side tube 113 is connected to the sheath connector 112, and the internal space of the side tube 113 is connected to the internal space of the sheath body 111. The channel inside the sheath body 111 is a delivery channel for the guide wire, the basket 21, etc.; the hemostatic valve 114 can adjust the aperture of its internal valve hole so that the guide wire, the basket 21 and the smaller pipe fittings can enter the inside of the sheath body 111 through the hemostatic valve 114. The side tube 113 can allow external cleaning fluid to enter the sheath tube body 111 so as to clean the sheath tube 111 .

[0076] like Figure 1 and Figure 2 As shown, the blood flow maintenance basket includes a basket 21, a push assembly and a loading tube 22. The basket 21 is a self-expanding structure, and the basket 21 has an expanded state in which it is radially expanded outward after the external force is removed, and a collapsed state in which it is radially collapsed inward under the constraint of the external force. The push assembly is connected to the basket 21, and the push assembly is used to push the basket 21 in the sheath tube 11. The loading tube 22 is movably sleeved on the outer periphery of the basket 21 in the collapsed state; the head end of the loading tube 22 can be inserted into the hemostatic valve 114 at the proximal end of the sheath tube 11.

[0077] As Figure 2 and Figure 4 shown, before the blood flow maintenance basket is inserted into the insertion sheath 11, the basket 21 is in a retracted state and constrained within the loading tube 22. When the blood flow maintenance basket is inserted into the insertion sheath 11, the loading tube 22 is inserted onto the hemostatic valve 114 within the sheath connector 112. The loading tube 22 allows the basket 21 therein to smoothly pass through the hemostatic valve 114 within the sheath connector 112 into the sheath body 111 under the action of the pushing assembly. When the basket 21 is pushed to the distal end of the sheath 11, the loading tube 22 can be retracted, and the hemostatic valve 114 adjusts the aperture of the internal valve hole to prevent blood from leaking through the sheath 11, reducing blood loss during the operation. After the basket 21 is released outward from the opening at the distal end of the sheath 11, it self-expands from the retracted state to the deployed state.

[0078] Specifically, the inner diameter dimension of the sheath body 111 is just large enough to convey the basket 21. The sheath body 111 can relatively easily convey and retrieve the basket 21, and at the same time ensure that when the basket 21 is deployed and the sheath body 111 is retracted to retrieve the basket 21, the opening at the distal end of the sheath body 111 can closely adhere to the basket 21, avoiding damage to blood vessels or causing displacement of the aortic covered stent during the process of retrieving the basket 21. Before the loading tube 22 is inserted into the sheath 11, to ensure that the sheath body 111 is just large enough to convey the basket 21, the dilator 12 is inserted into the sheath body 111 of the sheath 11. The dilator 12 dilates the sheath body 111. After the sheath body 111 is dilated, it is just large enough to convey the basket 21. Then the dilator 12 is withdrawn, and then the loading tube 22 is inserted into the sheath 11.

[0079] Figure 10 is a schematic diagram of the positional relationship among the basket 21, the aortic covered stent 3, and the blood vessel wall 5, where the cross-section of the basket 21 is circular. Figure 11 is a schematic diagram of the positional relationship among the basket 21, the aortic covered stent 3, and the blood vessel wall 5, where the cross-section of the basket 21 is oval. In Figure 10 and Figure 11 , the channel inside the aortic covered stent 3 is the blood flow channel 31 within the covered stent, the internal channel of the basket 21 and the cavity within the blood vessel wall 5 that is not occupied by the basket 21 and the aortic covered stent 3 outside the basket 21 is the blood flow channel 4 outside the covered stent. From Figure 10 and Figure 11 , it can be seen that the setting of the basket 21 within the blood vessel wall 5 can form the blood flow channel 4 outside the covered stent in the aortic covered stent 3, so that the blood flow within the blood vessel can flow through the blood flow channel 4 outside the covered stent into the basket 21 and further flow to the branch vessels of the aortic arch, maintaining the normal flow of blood within the branch vessels.

[0080] During the endovascular exclusion treatment of the aortic arch, the blood flow maintenance device is used in cooperation with the aortic covered stent 3 and the membrane puncturing instrument during the windowing process of the aortic covered stent. Before the aortic covered stent 3 is released into the aortic arch, the basket 21 of the blood flow maintenance device is released on the convex side of the aortic arch. The basket 21 separates the aortic covered stent 3 to be windowed from the vascular wall 5 on the convex side, forming an extracorporeal blood flow channel 4 outside the covered stent, ensuring that the blood flow in the branch vessels is not blocked during the windowing process of the aortic covered stent 3. After the membrane puncturing instrument finishes windowing on the aortic covered stent 3, the branch artery stent is implanted, and finally the blood flow maintenance basket is withdrawn, so that the aortic covered stent 3 can be attached to the aortic arch.

[0081] As Figure 6 and Figure 7 shown, the pushing assembly includes an outer tube 23, an outer tube handle 24, a mandrel 25 and a mandrel handle 26; the distal end of the outer tube 23 is fixedly connected to the proximal end of the basket 21, and the proximal end of the outer tube 23 is connected to the outer tube handle 24; the mandrel 25 is coaxially disposed in the inner cavity of the outer tube 23, the distal end of the mandrel 25 is fixedly connected to the distal end of the basket 21, and the proximal end of the mandrel 25 passes through the outer tube handle 24 and is connected to the mandrel handle 26; the mandrel handle 26 drives the distal end of the basket 21 to move through the mandrel 25, and the outer tube handle 24 drives the proximal end of the basket 21 to move through the outer tube 23. This basket 21 with both ends fixed can jointly control the movement of the distal end of the basket 21 through the mandrel handle 26 and the mandrel 25; among them, the outer tube handle 24 and the outer tube 23 control the movement of the proximal end of the basket 21, and the mandrel handle 26 and the mandrel 25 can control the movement of the distal end of the basket 21. The two cooperate to control the unfolding state of the basket 21, which is convenient to release the basket 21 in a suitable shape on the convex side of the target position to be covered by the aortic covered stent 4, and is also convenient for subsequent recovery of the basket 21.

[0082] As Figure 7 and Figure 8 shown, the basket 21 is in a lantern shape in the unfolded state. The basket 21 includes a basket main body part 211 in the shape of a net tube, a proximal connecting part 212 located at the axial proximal end of the basket main body part 211, and a distal connecting part 213 located at the axial distal end of the basket main body part 211; the basket main body part 211 is the part with a larger outer diameter in the middle of the basket 21 in the unfolded state, and the proximal connecting part 212 and the distal connecting part 213 are the parts with narrowed ends at both ends of the basket 21 in the unfolded state. 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 mandrel 25. The basket main body part 211, the proximal connecting part 212 and the distal connecting part 213 are of an integral structure.

[0083] As Figure 7 and Figure 8As shown, the wire basket 21 further 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 inner steel sleeve and an outer steel sleeve in a ring shape. The proximal connecting portion 212 of the wire basket 21 is placed between the inner steel sleeve and the outer steel sleeve and fixed to the proximal fixing sleeve 214 by means such as laser welding, brazing, and 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 wire basket 21 through the distal steel sleeve. Specifically, the distal end of the mandrel 25 is inside, the distal connecting portion 213 of the wire basket 21 is in the middle, the distal steel sleeve is constrained outside the distal connecting portion 213, and the distal end of the mandrel 25, the distal connecting portion 213, and the distal steel sleeve are fixed by brazing, laser, or bonding. The distal end of the outer tube 23 is fixedly connected to the proximal fixing sleeve 214 by means such as laser welding, brazing, and bonding, so as to fix both ends of the wire basket 21.

[0084] As Figure 7 and Figure 9 shown, the loading tube 22 is a tubular structure. Before the blood flow maintaining wire basket is inserted into the sheath tube, the wire 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 a side tube.

[0085] As Figure 7 and Figure 8 shown, the main body portion 211, the proximal connecting portion 212, and the distal connecting portion 213 of the wire basket are a continuous lantern-shaped structure formed by single wire interweaving; among them, the wire basket 21 is thermally formed into the final deployed form through a tooling. Specifically, as Figure 12 and Figure 13 shown, taking the single wire woven wire basket as an example, a single metal wire can be wound into a waveform along the piles on the sizing mandrel, then woven around the tooling for one week and wound and fixed to the original metal wire at the wire overlapping part, and then the second layer of piles is wound and hooked to the waveform of the first layer of brackets to form an integral body. In the same way, continue to wind to form a long strip-shaped woven wire basket. After the wire basket 21 is thermally formed through the tooling, the piles on the mandrel are pulled out, and the woven wire basket is taken off, and the wire basket is thermally formed into the final deployed form. The length change of this single wire woven wire basket 21 in the deployed state can be controlled within a relatively small range. During and after the windowing process, the wire basket 21 can be more smoothly retracted into the sheath tube with as little impact as possible on the release position of the aortic covered stent, and the operation is relatively simple. In Figure 12 and Figure 13 , 21a is the weaving starting point, 21b is the weaving ending point, and 21c is the overlapping winding part of the weaving wire.

[0086] In the process of intracavitary isolation treatment of the aortic arch, before the aortic stent graft is released, the basket 21 is first pushed outward from the distal opening of the sheath tube 11 by using the pushing assembly. After being released from the sheath tube 11, the basket 21 is in an expanded state, and the internal cavity of the basket 21 can form a blood flow channel; after the aortic stent graft 3 is released, the basket 21 will be supported on one side of the aortic stent graft 3, and a blood flow channel 4 outside the stent graft will be formed on the outside of the aortic stent graft, and the blood flow can smoothly enter the branch blood vessels on the arch through the blood flow channel 4 outside the stent graft, thereby ensuring the blood supply to the head during the fenestration of the aortic stent graft; the time limit of the fenestration of the aortic stent graft is eliminated, making the in situ fenestration for the intracavitary isolation diagnosis and treatment of the arch simple and popularizable. By adopting this blood flow maintenance basket, the difficulty of intracavitary isolation treatment of the aortic arch can be reduced, the operation time can be shortened, and the requirements for hospital conditions and the operator's operation level can be reduced. At the same time, it is conducive to reducing postoperative complications and promoting the operation.

[0087] Embodiment 2

[0088] like Figure 14 The blood flow maintaining device shown is different from the embodiment 1 in that the weaving method of the basket 21 is different. The basket 21 is formed by a mesh tube structure formed by a plurality of strands of metal wires, or a basket structure formed by laser engraving of a nickel-titanium tube. The structure of the pushing component is the same as that of the embodiment 1.

[0089] Embodiment 3

[0090] like Figure 15 - Figure 20 The blood flow maintaining device shown is different from the first embodiment in that the structures of the basket 21 and the pushing assembly are different. The pushing assembly 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 in 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 basket 21 is a self-expanding basket. The basket 21 includes a basket body 211 and a proximal connection portion 212 located at the axial proximal end of the basket body 211. The basket body 211 is in a net tube shape when in the expanded state. The proximal connection portion 212 is a portion of the basket 21 that is narrowed at the proximal end when in the expanded state. The distal end of the basket body 211 is open, and the basket 21 is not provided with a distal narrowing portion for closing the distal end of the basket body 211. The proximal connection portion 212 is fixedly connected to the distal end of the connecting rod 27 through a proximal fixing sleeve 214, so as to achieve the fixation of one end of the basket 21. The basket 21 with a proximal fixed end can be controlled to move by a handle 28 and a connecting rod 27, and has a simple structure and is easy to operate.

[0091] Embodiment 4

[0092] like Figure 21 The blood flow maintenance device shown is different from the second embodiment in that the weaving method of the basket 21 in the blood flow maintenance basket is different. The basket 21 is formed by a mesh tube structure formed by a plurality of strands of metal wires, or a basket structure formed by laser engraving of a nickel-titanium tube. The proximal end of the basket 21 is provided with a proximal fixing sleeve 214 for narrowing the basket 21, and the distal end of the basket 21 is provided with a distal fixing sleeve 215 for narrowing 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 easy to deform.

[0093] Embodiment 5

[0094] like Figure 22 The blood flow maintenance device shown is different from the fourth embodiment 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 is not provided with a distal narrowing portion for closing the distal end of the basket 21. This basket has a simple structure and is easy to manufacture.

[0095] Embodiment 6

[0096] like Figure 23 The blood flow maintenance basket shown is different from the third embodiment 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 connected between two adjacent small baskets 216; the small basket 216 is lantern-shaped in the expanded state, the distal end of the connecting rod 217 is connected to the axial proximal end of a small basket 216 located at the distal end of the two adjacent small baskets 216, and the proximal end of the connecting rod 217 is connected to the axial distal end of a small basket 216 located at the proximal end of the two adjacent small baskets 216. It can be understood here that the number of small baskets 216 is not limited to four, but can also be three or more. Each window position on the aortic stent graft 3 corresponds to a branch vessel; when the basket 21 is released from the distal opening of the sheath 11 and is in the expanded state, each small basket 216 is supported at one of the window positions on the aortic stent graft 3 to ensure the blood supply of the corresponding branch vessel. During the process of retracting the basket 21 in the expanded state into the sheath tube 11, the multiple small baskets 216 can be sequentially retracted into the sheath tube 11. With this multi-section basket structure, when the sheath tube retracts the basket 21, since the retracting of a small basket 216 is less affected by the other parts of the entire basket 21, the operation of retracting a small basket 216 at a time is easier than the operation of retracting a part of the entire basket 21 at a time, and it can also avoid the length of the basket being retracted too long when the sheath tube retracts the basket 21; and the two adjacent small baskets 216 are easy to bend and deform, which can better conform to the tortuous blood vessels.

[0097] Embodiment VII

[0098] As Figure 24 shown, a blood flow maintenance device, which is different from that in Embodiment VI in that the structure of the basket 21 is different. Three restraint rings 218 are sleeved on the basket 21 in the length direction, and the part of the basket 21 sleeved by the restraint rings 218 is locally narrowed. The basket 21 forms four small baskets 216 arranged in sequence under the restraint of the restraint rings 218. The small baskets 216 are in a lantern shape in the unfolded state, and adjacent two small baskets 216 are separated by the restraint rings 218. It can be understood here that the number of the restraint rings 218 on the basket 21 is not limited to three, and can also be two or more. When manufacturing the basket 21 in this multi - section structure form, an integral tubular net basket can be manufactured first, and then the three restraint rings 218 are used to narrow the tubular net basket at three quarter - nodes in the length direction of the tubular net basket, and the basket in the multi - section structure form can be obtained. This basket 21 in the multi - section structure form is not only convenient for recycling one small basket 216 at a time compared with the basket in Embodiment VI, avoiding the excessive length of the basket recycled at one time when the sheath tube recycles the basket 21, but also has a simpler manufacturing method.

[0099] Embodiment IX

[0100] As Figure 25 - Figure 31 shown, an aortic covered stent system includes an aortic covered stent 3, a delivery device (not shown in the figure), a membrane - piercing instrument 7, a branch artery stent 8, and a blood flow maintenance device as described in any one of the above embodiments. Among them, the sheath tube 11 of the blood flow maintenance device can be pushed to the distal end of the target position to be covered by the aortic covered stent. The pushing assembly of the blood flow maintenance device can push the basket 21 in the sheath tube 11, and the basket 21 unfolds from the retracted state to the unfolded state after being released outward from the distal opening of the sheath tube 11. The delivery device is used to deliver the aortic covered stent 3 to one side of the basket 21 in the unfolded state. The basket 21 supports the aortic covered stent 3 and forms an extracorporeal - covered - stent blood flow channel 4 outside the aortic covered stent 3. The membrane - piercing instrument 7 is used to create a window at the position to be windowed on the membrane of the aortic covered stent 3 delivered to the target position to be covered by the aortic covered stent. The branch artery stent 8 is used to be released at the windowed position on the membrane of the aortic covered stent 3. The sheath tube 11 is used to recycle part of the basket 21 before the membrane - piercing instrument 7 creates a window to make way for the position to be windowed on the membrane of the aortic covered stent 3, and to completely recycle the basket 21 and withdraw from the target position to be covered by the aortic covered stent 3 after the aortic covered stent 3 has been windowed.

[0101] Figure 25It is a schematic diagram of the thoracic aorta. Among them, the aortic arch 61 is the part of the upper aorta that bends in an arc. Three relatively large arteries branch out from the convex side of the arch, which are successively divided into the brachiocephalic trunk 64 (innominate artery), the left common carotid artery 65, and the left subclavian artery 66 from left to right. The front end of the aortic arch 61 is connected to the ascending aorta 63, and the rear end of the aortic arch 61 is connected to the descending aorta 62.

[0102] Such as Figure 26 - Figure 31 It is a schematic diagram of the process of in-situ fenestration of an aortic covered stent in the thoracic aorta. When the target position to be covered by the aortic covered stent 3 is the aortic arch 61, before the aortic covered stent 3 is implanted into the aortic arch 61, the sheath 11 is delivered to the aortic arch 61 through a guide wire. After the distal end of the sheath 11 exceeds the position of the ascending aorta 63 that the aortic covered stent 3 is intended to cover, the dilator 12 is inserted into the sheath 11 to dilate the sheath 11. After the sheath 11 is dilated, the dilator 12 and the guide wire are withdrawn. The basket 21 of the blood flow maintaining device is retracted 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 pushing assembly advances the basket 21 until the basket 21 in the retracted state is pushed to the distal end of the sheath 11. Then the sheath 11 is retracted a certain distance, so that the basket 21 in the retracted state is released outward from the distal opening of the sheath 11 and deployed on the convex side of the aortic arch 61. Then the aortic covered stent 3 is released into the aortic arch 61. Since the deployed basket 21 is located on the convex side of the aortic arch 61, the aortic covered stent 3 released in the thoracic aortic arch 61 cannot fit with the blood vessel wall 5 on the convex side. Blood can flow into the branch vessels above the arch through the inside of the basket 21 and the gaps around the basket 21, thus ensuring normal blood supply to the branch vessels during the fenestration process of the aortic covered stent 3 and solving the problem of head ischemia during in-situ fenestration of the aortic covered stent 3.

[0103] After the aortic covered stent 3 is released, fenestrations are made in the supra-aortic branches from the back to the front. The wire basket 21 is fixed, and the sheath 11 is pushed forward to the leading edge of the branch vessel to be fenestrated. In this way, blood flow can continuously supply the branch vessel to be fenestrated and the previous branch vessels, and at the same time, it can effectively prevent the membrane puncturing device 7 from passing through the wire basket 21 (if the membrane puncturing device 7 passes through the wire basket 21, it will cause difficulties in retrieving the wire basket 21 or delay or failure in the fenestration process). After using the membrane puncturing device 7 to penetrate the covering membrane at this branch, a guide wire is inserted, and then a balloon is inserted along the guide wire to expand the covering membrane at this position to form a window. After the fenestration of the window of this branch is completed, a branch artery stent 8 with a matching specification can be implanted in the window and the branch vessel to achieve the reconstruction of the branch vessel or, after the fenestrations at all the openings of the branch vessels are completed, the branch vessels are reconstructed through the branch artery stent 8. The wire basket 21 is fixed, and the sheath 11 is continuously advanced so that the distal end of the wire basket 21 is retrieved into the sheath 11 until the distal end of the sheath 11 reaches the leading edge of the next branch vessel to be fenestrated. In this way, the blood flow supply of the branch vessel to be fenestrated can be ensured, and at the same time, the already fenestrated or reconstructed branches can also maintain sufficient blood flow supply. The same method is used for the fenestration of the previous branch vessel. Until all the branch vessels are fenestrated, the wire basket 21 is fixed, and the sheath 11 is slowly and continuously advanced so that the wire basket 21 is completely retrieved backward into the sheath 11. The sheath 11 is withdrawn so that the aortic covered stent 3 fits completely with the blood vessel wall 5.

[0104] Specifically, after the aortic covered stent 3 is fully deployed, it is preferable to perform the fenestration of the supra-aortic branches from the back to the front. When specifically performing the fenestration of a branch vessel, the sheath 11 is advanced to receive the wire basket 21 at this branch vessel and the subsequent part into the sheath 11. After the covering membrane is fenestrated, the wire basket 21 is retrieved, and then the branch stent is inserted to achieve the reconstruction of the branch vessel. Thereby, the limitation of the fenestration time at the aortic arch is eliminated, making the in-situ fenestration for endovascular aortic arch repair simple and popularizable; moreover, it can improve the postoperative effect and reduce the complications during the operation. The present invention mainly solves the problems in the in-situ fenestration branch reconstruction process of the total branch endovascular reconstruction surgery of the aortic arch, that is, extracorporeal circulation or deep hypothermic circulatory arrest is required to solve cerebral ischemia during the in-situ fenestration branch reconstruction process, and the surgical operation is difficult and the complication ratio is too high. It makes the endovascular aortic arch repair with in-situ fenestration of the aortic arch lesions simple and easy to perform.

[0105] Embodiment Ten

[0106] As Figure 32 shown in an aortic covered stent system, which is different from Embodiment Nine in that the aortic covered stent system further includes two bypass sheaths 9 and a connecting tube 91.

[0107] The bypass sheath 9 is specifically a sheath tube with a size of 10F - 16F. The difference between the bypass sheath 9 and a conventional vascular sheath lies in that the inner diameter of the side tube of the bypass sheath 9 is different. The inner diameter of the side tube and the valve inner diameter of the bypass sheath 9 are close to or larger than the inner diameter of the sheath tube, enabling the bypass function to be achieved through the side tube. At the same time, the hemostatic valve has the function of not leaking through multiple instruments. The connecting tube 91 is used to connect the side tubes of the two bypass sheaths inserted into the left and right common carotid arteries. The inner diameter of the connecting tube 91 is close to or larger than the inner diameter of the bypass sheath, ensuring the bypass flow rate. This aortic covered stent system can be used for double fenestration (fenestration of the left common carotid artery and the left subclavian artery) or triple fenestration.

[0108] During the double fenestration operation, a blood flow maintenance device can be combined with a conventional 8 - 10F vascular sheath or with the bypass sheath 9. Before implanting the aortic covered stent, insert the bypass sheath 9 into the left common carotid artery until the front end of the bypass sheath 9 reaches the opening of the branch vessel. Then, send a blood flow maintenance basket into the bypass sheath 9 until the end of the basket just exceeds the nozzle of the bypass sheath 9. Then, establish an access for fenestration of the left subclavian artery. After preparation, release the aortic covered stent at the expected position. Then, retract the sheath tube of the blood flow maintenance device outside the sheath tube of the vascular sheath, and the basket will expand automatically. A space for blood flow is formed outside the aortic covered stent. Insert a puncture needle, etc. through the film from the sheath tube of the vascular sheath, send a guide wire, and then expand the balloon along the guide wire to achieve in-situ fenestration of the left common carotid artery. Then, send the sheath of the blood flow maintenance device, and retract the basket into the sheath tube by advancing the sheath tube of the blood flow maintenance device, and then withdraw the whole inside the vascular sheath. Then, perform fenestration on the left subclavian artery, and then complete the reconstruction of the left common carotid artery and the left subclavian artery respectively through branch artery stents.

[0109] During the three-window surgery, perfusion sheaths 9 are respectively inserted into the left and right common carotid arteries through punctures, and the front ends of the perfusion sheaths 9 reach the openings of the branch vessels. A blood flow maintenance device is inserted into the right common carotid artery until the end of the basket just exceeds the sheath orifice of the perfusion sheath 9, and then a windowing approach to the left subclavian artery is established. Then, the connecting tube 91 is connected to the side tubes of the two perfusion sheaths 9. After exhausting the air, the aortic covered stent is released at the expected position, and then the sheath tube of the blood flow maintenance device is retracted outside the sheath tube of the vascular sheath group, and the basket 21 unfolds automatically. A space for blood flow is formed outside the aortic covered stent in the ascending aorta segment. Blood flows through this space into the brachiocephalic trunk artery and flows out from the perfusion sheath 9 of the right common carotid artery, and then flows into the perfusion sheath 9 of the left common carotid artery through the connecting tube 91 and then into the left carotid artery. Next, a puncture needle or the like is inserted into the perfusion sheath 9 of the left common carotid artery to penetrate the covered membrane. After inserting a guide wire, a balloon is then inserted along the guide wire to expand and achieve in-situ windowing of the left common carotid artery. Then, a puncture needle or the like is inserted into the perfusion sheath 9 of the right common carotid artery to penetrate the covered membrane. After inserting a guide wire, a balloon is then inserted along the guide wire to expand and achieve in-situ windowing of the brachiocephalic trunk artery. Then, the sheath of the blood flow maintenance device is inserted into the perfusion sheath 9 of the right common carotid artery, and the sheath tube of the blood flow maintenance device is advanced to retract the basket into the sheath tube, and then the entire vascular sheath is withdrawn. Then, a window is made in the left subclavian artery, and the brachiocephalic trunk, left common carotid artery, and left subclavian artery are respectively reconstructed with peripheral vascular covered stents.

[0110] Example XI

[0111] Example XI of the present invention provides a method for windowing an aortic covered stent, comprising the following steps:

[0112] Step S1: Before implanting the aortic covered stent 3 at the target position, advance the distal end of the sheath tube 11 to the target position covered by the aortic covered stent 3;

[0113] Step S2: Advance the basket 21 in the retracted state to the distal end of the sheath tube 11, retract the sheath tube 11 by a certain distance, and the basket 21 is released outward from the opening at the distal end of the sheath tube 11 and self-expands and unfolds on the large curvature side of the target position;

[0114] Step S3: Implant the aortic covered stent 3 at the target position, and the unfolded basket 21 is located between the aortic covered stent 3 and the large curvature side of the target position;

[0115] Step S4: Advance the sheath tube 11 by a certain distance, and the unfolded basket 21 is partially retracted and recovered into the sheath tube 11, making way for the windowing position corresponding to the aortic covered stent 3 and the large curvature side of the target position;

[0116] Step S5: Insert the membrane puncturing device 7 into the fenestration position of the aortic covered stent 3. The membrane puncturing device 7 creates a window in the membrane of the aortic covered stent 3, and a stent window 32 is formed on the membrane. Repeat steps S5 and S6 three times until three stent windows 32 are formed on the membrane.

[0117] Step S6: After the fenestration of the three stent windows 32 on the aortic covered stent 3 is completed, advance the sheath 11. The basket 21 in the deployed state is completely retracted into the sheath 11, and the sheath 11 is withdrawn from the target position covered by the aortic covered stent 3.

[0118] Step S7: Insert branch artery stents 8 with matching specifications into the branch vessels through the three stent windows 32 to achieve branch vessel reconstruction.

[0119] The key point of the fenestration method of the aortic covered stent of the present invention is: first release the basket 21, use the basket 21 to separate the aortic covered stent 3 to be fenestrated from the large curvature vascular wall 5, so that during the fenestration process, blood flow can continuously supply the supra-aortic branch vessels, ensuring that the branch blood flow will not be interrupted during the fenestration process.

[0120] Obviously, the above embodiments are only examples for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A blood flow maintenance device, characterized in that, The invention comprises a delivery sheath and a blood flow maintaining basket, wherein the delivery sheath comprises a sheath tube (11), and the blood flow maintaining basket comprises a basket (21) and a pushing assembly; the basket (21) has an expanded state in which it is expanded radially outward and a collapsed state in which it is collapsed radially inward; the pushing assembly is connected to the basket (21), and the pushing assembly is used to push the basket (21) in the sheath tube (11); when the basket (21) is released outward from the distal end opening of the sheath tube (11) and is in the expanded state, the basket (21) is suitable for supporting an aortic stent graft (3) and forming a stent graft blood flow channel (4) outside the stent graft on the outside of the supporting aortic stent graft (3).

2. The blood flow maintenance device according to claim 1, characterized in that, The pushing assembly comprises an outer tube (23), an outer tube handle (24), a core shaft (25) and a core shaft 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 core shaft (25) is coaxially arranged in the inner cavity of the outer tube (23), the distal end of the core shaft (25) is fixedly connected to the distal end of the net basket (21), and the proximal end of the core shaft (25) is connected to the core shaft handle (26) after passing through the outer tube handle (24); the core shaft handle (26) drives the distal end of the net basket (21) to move through the core shaft (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) is expanded or retracted under the control of the core shaft handle (26) and the outer tube handle (24).

3. The blood flow maintenance device according to claim 2, characterized in that The net basket (21) comprises a net basket main body (211), a proximal connecting part (212) located at the axial proximal end of the net basket main body (211), and a distal connecting part (213) located at the axial distal end of the net basket main body (211); the net basket (21) is lantern-shaped in the unfolded state, the net basket main body (211) is the middle part of the net basket (21) with a larger outer diameter in the unfolded state, the proximal connecting part (212) and the distal connecting part (213) are the parts of the net basket (21) with narrowed ends in the unfolded state; 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 core shaft (25).

4. The blood flow maintaining device according to claim 1, characterized in that, The pushing assembly comprises a connecting rod (27) and a handle (28), wherein 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 in the sheath tube (11) via the connecting rod (27).

5. The blood flow maintaining device according to claim 4, characterized in that, The net basket (21) is a self-expanding net basket, and the net basket (21) comprises a net basket main body (211) and a proximal connecting portion (212) located at the axial proximal end of the net basket main body (211); the net basket main body (211) is in the shape of a net tube in the unfolded state, and the proximal connecting portion (212) is a portion of the net basket (21) that is narrowed at the proximal end in the unfolded state, and the proximal end of the proximal connecting portion (212) is fixedly connected to the distal end of the connecting rod (27).

6. The blood flow maintaining device according to claim 4, wherein The net basket (21) comprises a plurality of small net baskets (216) arranged in sequence and a connecting rod (217) connected between two adjacent small net baskets (216); the small net baskets (216) are in the shape of a lantern in the unfolded state, the distal end of the connecting rod (217) is connected to the axial proximal end of a small net basket (216) located at the distal end of two adjacent small net baskets (216), and the proximal end of the connecting rod (217) is connected to the axial distal end of a small net basket (216) located at the proximal end of two adjacent small net baskets (216); or the net basket (21) is sleeved with a plurality of restraining rings (218) in the length direction, the part of the net basket (21) sleeved by the restraining rings (218) is locally narrowed, and the net basket (21) forms a plurality of small net baskets (216) arranged in sequence under the restraint of the restraining rings, and the small net baskets (216) are in the shape of a lantern in the unfolded state.

7. The blood flow maintaining device according to any one of claims 1-6, characterized in that, The blood flow maintaining device also includes a loading tube (22), which is movably sleeved on the outer circumference of the mesh basket (21) in a folded state, and the loading tube (22) is suitable for being inserted into the proximal opening of the sheath tube (11) to allow the mesh basket (21) therein to be inserted into the sheath tube (11) under the action of the pushing component.

8. The blood flow maintaining device according to claim 7, wherein The delivery sheath further comprises a dilator (12) for dilating the sheath tube (11); the pushing assembly is used to push the net basket (21) inside the sheath tube (11) and enable the net basket (21) to be released outward from the distal opening of the sheath tube (11) and then expanded from the retracted state to the expanded state; the sheath tube (11) is suitable for moving toward the distal end under the action of an external pushing force so as to retract the net basket (21) in the expanded state and then recover it into the sheath tube (11).

9. An aortic covered stent system, characterized in that, It comprises an aortic stent graft (3), a delivery device, a membrane rupturing device (7) and a blood flow maintaining device as described in any one of claims 1 to 8 used in combination; The pushing component is used to push the net basket (21) in the sheath tube (11), and the net basket (21) is released outward from the distal end opening of the sheath tube (11) and then expanded from the retracted state to the expanded state; The conveying device is used to convey the aortic stent graft (3) to one side of the basket (21) in the expanded state, and the basket (21) supports the aortic stent graft (3) and forms a stent graft outer blood flow channel (4) on the outer side of the supporting aortic stent graft (3); The sheath tube (11) is used to retract part of the basket (21) before windowing the membrane-breaking device to clear the position to be windowed on the membrane of the aortic covered stent (3); The membrane-breaking device (7) is used to make a window at the position to be windowed on the membrane of the aortic covered stent (3); The sheath tube (11) is further used to completely retract the basket (21) and withdraw from one side of the aortic covered stent (3) after the aortic covered stent (3) is windowed; 10. A fenestration method for an aortic covered stent, based on the aortic covered stent system according to the above-mentioned claim 9, characterized in that, It includes the following steps: S1. Before the aortic covered stent is implanted at the target position, the distal end of the sheath tube is advanced to the distal end of the target position to be covered by the aortic covered stent; S2. The basket in the retracted state is advanced to the distal end of the sheath tube, the sheath tube is retracted a certain distance, and the basket is released outward from the distal opening of the sheath tube and unfolds on the large curvature side of the target position to be covered by the aortic covered stent; S3. The aortic covered stent is implanted at the target position to be covered by the aortic covered stent, and the unfolded basket is supported between the aortic covered stent and the large curvature side of the target position to be covered by the aortic covered stent; S4. The sheath tube is advanced a certain distance, and the unfolded basket is partially retracted and recovered into the sheath tube to clear the position to be windowed on the membrane of the aortic covered stent; S5. The membrane-breaking device is implanted at the position to be windowed on the membrane of the aortic covered stent, and the membrane-breaking device makes a window at the position to be windowed on the membrane of the aortic covered stent; S6. After the windowing at the position to be windowed on the membrane of the aortic covered stent is completed, the sheath tube is advanced, and the unfolded basket is completely recovered into the sheath tube, and finally the sheath tube is withdrawn from the target position to be covered by the aortic covered stent.

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