Using a multibranched stent graft to treat thoracoabdominal aortic aneurysms

Inclusion Criteria:

1. Age ≥18 and ≤80 years;
2. Patients diagnosed with thoracoabdominal aortic aneurysm (based on the modified Crawford classification and the 2019 European guidelines for the treatment of aortic aneurysms), and should meet at least one of the following conditions:

   1. Maximum diameter of TAAA \>50 mm,
   2. Rapid growth of sac \>5 mm in diameter in the most recent 6 months, or rapid growth \>10 mm in diameter within 1 year
   3. Symptoms related to thoracoabdominal aortic aneurysm, such as clear abdominal pain and back pain.
3. Anatomical criteria, including:

   1. Proximal landing zone 17-36 mm in diameter and ≥25 mm in length
   2. If distal landing zone in abdominal aorta:Distal landing zone 12-36 mm in diameter and ≥20 mm in length If distal landing zone in iliac artery:Distal landing zone 7-25 mm in diameter and ≥15 mm in length
   3. Visceral vessel landing zone 6-13 mm in diameter and ≥15 mm in length
   4. Renal artery landing zone 4.5-9 mm in diameter and ≥15 mm in length
4. Patients with Feasible iliofemoral artery and upper patent upper extremity access;
5. Patients who can understand the purpose of the trial, voluntarily participate and sign the informed consent form, and are willing to complete the follow-up according to the requirements of the protocol;

Exclusion Criteria:

1. Ruptured aortic aneurysm in unstable haemodynamic condition;
2. Aneurysmal aortic dissection;
3. Infected or mycotic aortic aneurysm;
4. Patients whose systemic or local infection may increase the risk of intravascular graft infection;
5. Patients with occlusion of the superior mesenteric artery, celiac trunk, or renal artery.
6. Requiring simultaneous coverage or embolisation for bilateral internal iliac arteries;
7. Severe stenosis, calcification, or mural thrombus at stent-graft landing zone;
8. Diagnosis of acute coronary syndrome within 6 months; Acute coronary syndrome refers to an acute cardiac ischemia syndrome caused by the rupture or erosion of unstable atherosclerotic plaques in the coronary arteries, which is followed by the formation of fresh thrombus. It includes ST-segment elevation myocardial infarction, non-ST-segment elevation myocardial infarction, and unstable angina pectoris.
9. Patients with any transient ischemic attack (TIA) or ischemic stroke within 3 months;
10. Preoperative liver renal function abnormalities (ALT or AST ≥ 5 times the upper limit of normal value), or serum creatinine ≥ 150 μmol/L;
11. Severe pulmonary insufficiency who cannot tolerate general anaesthesia;
12. Severe coagulation dysfunction;
13. Undergone major surgical or interventionic surgery within 30 days before surgery;
14. An allergic history for contrast agents, anticoagulants, antiplatelet drugs, stent graft or materials of delivery system( (referring to nickel-titanium, polyester, PTFE, nylon-based polymer materials);
15. Patients with connective tissue diseases, such as systemic lupus erythematosus, Marfan syndrome, Ehlers-Danlos syndrome, or Behcet's disease;
16. Patients with takayasu arteritis;
17. Patients with serious vital organ dysfunction or other serious disease;
18. Planning pregnancy, pregnancy, or breastfeeding;
19. The patient participated in other clinical trials or not completed or withdrawn from other clinical trials within the last 3 months at the time of screening period ;
20. Life expectancy less than 1 year;
21. Patients who are not appropriate for endovascular repair based on the investigators' clinical judgement.