Safety and Efficacy of a Multi-branched Thoracoabdominal Stent Graft System for Thoracoabdominal Aortic Aneurysm.

Inclusion Criteria:

1. 18 years old ≤ age ≤ 80 years old;

2. Diagnosed as thoracoabdominal aortic aneurysm (based on modified Crawford classification and 2019 European Guidelines for the Treatment of Aortic aneurysm) and should meet at least one of the following conditions;

   1. Maximum diameter of thoracoabdominal aortic aneurysm>50mm;
   2. The diameter has increased by more than 5mm in recent 6 months or the by more than 10mm in recent 1 year;

3. anatomical criteria

   1. The proximal anchoring region (aorta or implanted graft) was 17~36 mm in diameter and ≥25 mm in length;
   2. Distal anchoring region (aorta or implanted graft): If the distal anchoring region is in the iliac artery, the anchoring region has a diameter range of 7~25 mm and a length of ≥15 mm; If the distal anchoring area is in the abdominal aorta, the diameter of the anchoring area ranges from 12~36mm and the length≥ 20mm;
   3. The diameter of the vessel anchoring area of the visceral branch ranges from 6~13 mm and the length ≥15 mm;
   4. The diameter of renal artery anchoring area ranges from 4.5~9mm, and the length ≥15 mm;
   5. Appropriate iliac, femoral and upper limb artery access;
4. Patients who can understand the purpose of the trial, voluntarily participate and sign the informed consent, and are willing to complete the follow-up according to the requirements of the protocol;

Exclusion Criteria:

1. Hemodynamically unstable patients with ruptured thoracoabdominal aortic aneurysms;
2. Thoracoabdominal aortic dissection;
3. Mycotic or infectious thoracoabdominal aortic aneurysm;
4. Patients whose systemic or local infection may increase the risk of intravascular graft infection;
5. Superior mesenteric, celiac, or renal artery occlusion;
6. Requiring simultaneous coverage and embolization of bilateral internal iliac arteries;
7. Severe stenosis, calcification, or mural thrombus in the anchoring area of the stent tend to have difficulty in attachment of the stent-graft or affect the patency of the stent;
8. A history of acute coronary syndrome within 6 months; Acute coronary syndrome is defined as an acute ischemic syndrome of the heart resulting from the rupture or erosion of unstable intracoronary atherosclerotic plaques followed by fresh thrombosis, including ST-segment elevation myocardial infarction, non-ST-segment elevation myocardial infarction, and unstable angina pectoris.
9. Transient ischemic attack (TIA) or ischemic/haemorrhagic 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. A history of allergy to contrast agents, anticoagulants, antiplatelet drugs, stents, and conveyor materials (nitinol, polyester, PTFE, nylon);
15. Connective tissue diseases such as systemic lupus erythematosus, Marfan's syndrome, Adam's syndrome, or Behcet's disease;
16. takayasu arteritis;
17. Serious vital organ dysfunction or other serious disease;
18. Planning pregnancy, pregnancy, or breastfeeding;
19. Patients who participated in other clinical trials and was not discontinued or withdrawn within the first 3 months of the screening period of this trial.
20. Life expectancy less than 1 year;
21. Patients who, in the judgment of the investigator, are not eligible for endotherapy.