Safety and Efficacy Study of WeFlow-JAAA Stent Graft System for Complex Abdominal Aortic Aneurysm(GREAT Study)

Inclusion Criteria: 1. Age 18-80 years old, regardless of gender; 2. Subjects who were diagnosed with Juxtarenal and Pararenal abdominal aortic aneurysms and needed to reconstruct the blood supply of superior mesenteric artery and bilateral renal arteries; 3. Have appropriate vascular conditions, mainly including: * The distance between the upper edge of the aneurysm and the lower edge of the opening of superior mesenteric artery ≥ 4mm; * The angle between the proximal aneurysm neck and the aortic long axis near the opening of superior mesenteric artery ≤ 60 ° ; * The aortic diameter at the opening of superior mesenteric artery ranges from 18 to 34 mm ； * The diameter range of the starting part of superior mesenteric artery is 5-12mm； * The diameter range of the initial part of bilateral renal arteries is 4.5-10mm; * Length of non bifurcated segment of superior mesenteric artery and renal artery ≥ 10mm; * Blood vessel diameter at the bifurcation of abdominal aorta ≥ 16mm； * The length of distal anchoring area of iliac artery ≥ 15mm; * The diameter range of distal anchoring area of iliac artery is 8-24mm; * With appropriate femoral artery、iliac artery and upper limb artery approaches, endovascular treatment can be performed. 4. Those who can understand the purpose of the trial, voluntarily participate in the study, sign the informed consent form by themselves or their legal representative, and are willing to complete the follow-up according to the protocol requirements. Exclusion Criteria: 1. Patients with ruptured abdominal aortic aneurysm, pseudoaortic aneurysm and dissecting aortic aneurysm with hemodynamic instability; 2. Infectious aortic disease, Takayasu arteritis, Marfan syndrome (or other connective tissue diseases); 3. Severe stenosis, calcification and mural thrombosis in the proximal anchoring area of the stent; 4. Other vascular diseases need to be intervened in the same operation (such as coronary artery and carotid artery) and the postoperative drug treatment scheme is affected; 5. There is a history of myocardial infarction, TIA or cerebral infarction in recent 3 months; 6. The subject has a history of abdominal aortic surgery or endovascular repair; 7. Patients with severe liver, kidney, lung and cardiac dysfunction before operation \[subjects with serum creatinine level \> 150umol / L; alanine aminotransferase (ALT) or aspartate aminotransferase (AST) exceeds 5 times the upper normal limit; total serum bilirubin (STB) subjects who exceed 2 times the upper limit of normal; subjects whose left ventricular ejection fraction is less than 50% by color Doppler echocardiography.\]; 8. Patients with acute systemic infection; 9. Patients with contraindications to antiplatelet agents and anticoagulants; 10. Subjects are allergic to contrast agents, anesthetics, stents and conveyor materials; 11. Subjects cannot tolerate anesthesia; 12. Subjects Women who are pregnant or lactating or who cannot use contraception during the trial; 13. Subjects whose life expectancy is less than 12 months (such as advanced malignant tumor); 14. Subjects have participated in clinical trials of other drugs or devices in the same period; 15. The researchers determine that the subjects' vascular conditions affect the revascularization of branch arteries or are combined with other diseases and are not suitable to participate in this study.