Cost-utility Analysis of Fenestrated Aortic Stents Versus Open Surgery for the Treatment of Complex Abdominal Aortic Aneurysms

Inclusion Criteria: 1. Presence of an abdominal aortic aneurysm greater than 50 mm in diameter, anatomically unsuitable for a standard infrarenal stent graft because of an inadequate infrarenal neck and for which a treatment by FEVAR or OR is considered. The AAA can be identified as follows, according to preoperative imaging: * Short-neck or juxtarenal aneurysm: if treated by OR, would require an infrarenal proximal aortic suture, regardless of the level of clamping. * Suprarenal aneurysm: if treated by OR, would require a suprarenal/supramesenteric/ supraceliac aortic cross clamping, and a proximal bevelled suture and/or a separate revascularization of at least one renal artery. * Type IV thoracoabdominal aneurysm: aneurysm extending up to the level of the diaphragm pillars, requiring a supracoeliac clamping with a proximal bevelled suture and/or separate revascularization of at least one renal artery if treated by open surgery. 2. Patients aged 18 and over 3. Patient who expressed a non-opposition to participating in the study. 4. Patient affiliated to the French healyh care system Exclusion Criteria: 1. Presence of a type I, II, III or V thoracoabdominal aneurysm according to the modified Crawford Classification. 2. Patients for whom an alternative surgical technique is being considered and listes below: laparoscopic aortic repair, hybrid repair, CHIMPS, surgeon modified stent grafting, in situ fenestrations. 3. Patients deemed at prohibitive risk for OR : * uncompensated cardiac failure with LVEF \<40% (NYHA class III and IV) * Coronary revascularization \< 1 month * Large myocardial ischemia \>3 segments not revascularized or not revascularizable * Non-revascularized or non-revascularizable unstable angina * Non-operable tight aortic stenosis (mean gradient \> 40 mmHg, valve area \< 1 cm2, peak transvalvular velocity \> 4 m/s) * Non operable significant mitral shrinkage (area \<1.5cm²) * FEV1 \< 50% of the theoretical value * Home oxygen therapy * Chronic renal failure with clearance \< 30 ml/min 4. presence of a main renal artery less than 4 mm in diameter 5. Special anatomical configurations: horseshoe kidney, pelvic kidney. 6. Lesions of "shaggy" aorta at the visceral segment or at the lower thoracic aorta 7. History of abdominal aortic surgery (open or endovascular) 8. Dissecting, infected, ruptured or painful aneurysm 9. Life expectancy less than 2 years 10. Person under judicial protection 11. Person under tutorship or curatorship 12. Pregnant or breastfeeding woman