Safety and Effectiveness Trial of the Ventana Fenestrated Stent Graft System

Inclusion Criteria: * Male or female at least 18 years old; * Informed consent understood and signed and patient agrees to all follow-up visits; * Have aortic aneurysm with maximum diameter ≥5.5cm, or between 4.5 and 5.5cm and rapidly expanding (\>0.5cm in six months), or \>50% larger than the normal aortic diameter * Anatomically eligible for the Bifurcated System per the FDA-approved indications for use (IFU) and for the Fenestrated Stent Graft System: * Adequate iliac/femoral access compatible with the required delivery systems * Non-aneurysmal infrarenal aortic neck \<15mm in length; * Most caudal renal artery to aortoiliac bifurcation length ≥70mm * SMA to aortoiliac bifurcation length ≥90mm; * Proximal non-aneurysmal aortic neck below the SMA with: diameter 18 to 34 mm; length ≥15 mm; angle ≤60° to the aneurysm sac; * Angle ≤60° (clock face) between the SMA and CA * Renal arteries both distal to the SMA by ≤35mm, within 30mm of each other axially, with 4 to 8mm lumen diameter, and with clock face angle of 90° to 210° to each other .Common iliac artery distal fixation site with: distal fixation length ≥15 mm; ability to preserve at least one hypogastric artery; diameter ≥10 mm and ≤23 mm; angle ≤90° to the aortic bifurcation. * The Endologix Fenestrated Proximal Extension Stent must have the ability to overlap the bifurcated stent graft by at least 3cm. * Aortic diameter at the most caudal renal artery of 18 to 36mm Exclusion Criteria: * Life expectancy \<2 years as judged by the investigator; * Psychiatric or other condition that may interfere with the study; * Participating in the enrollment or 30-day follow-up phase of another clinical study; * Known allergy to any device component; * Coagulopathy or uncontrolled bleeding disorder; * Contraindication to contrast media or anticoagulants; * Ruptured, leaking, or mycotic aneurysm; * Aortic dissection * Serum creatinine (S-Cr) level \>2.0 mg/dL; * Traumatic vascular injury; * Active systemic or localized groin infection; * Connective tissue disease (e.g., Marfan's Syndrome); * Recent (within prior three months) cerebrovascular accident or myocardial infarction; * Prior renal transplant; * Length of either renal artery to be stented \<13mm; * Significant occlusive disease of either renal artery (\>70% stenosis); * An essential accessory renal artery; * Indispensable inferior mesenteric artery; * Aneurysmal disease of the descending thoracic aorta; * Clinically significant mural thrombus circumferentially in the suprarenal segment; * Prior iliac artery stent implanted that may interfere with delivery system introduction; * Unsuitable vascular anatomy; * Pregnancy (female patient of childbearing potential only) * Existing renal stent; * Pre-planned need for concomitant procedure (e.g. surgical conduit for vascular access, hypogastric artery embolization/coil, renal artery angioplasty)