The purpose of this study is to determine whether the Endologix fenestrated stent graft system is safe and feasible in the endovascular repair of juxtarenal or pararenal aortic aneurysm.

Inclusion Criteria:

• Informed consent understood and signed and pt agrees to all follow-up visits;
• Abdominal aortic aneurysm with diameter ≥5cm or ≥4cm which has increased by 0.5cm or more in the past six months
• 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 at least 70mm
• Proximal non-aneurysmal aortic neck below the SMA with: diameter 18 to 34 mm; length at least 15 mm; angle (clock face) <60° to the aneurysm sac;
• Angle <60° (clock face) between the SMA and celiac artery
• Renal arteries both distal to the SMA by 0-35mm, within 30mm of each other axially, with 4 to 8mm lumen diameter, and with clockface angle of 90° to 210° to each other
• Iliac anatomy suitable for commercial bifurcated stent graft;
• Minimum 3cm overlap achievable between fenestrated and bifurcated stent grafts

Exclusion Criteria:

• Life expectancy <1 year 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, dissecting, or mycotic aneurysm;
• 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 or calcification of either renal artery;
• An essential accessory renal artery;
• Indispensable inferior mesenteric artery;
• Untreated 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)