This study was a prospective observational study examined the safety of the TriVascular AAA Stent-Graft System in the elective treatment of patients with abdominal aortic aneurysms. Specifically, the study will evaluate the safety of the TriVascualr AAA Stent-Graft System, evaluate the ability to deliver the Tri-Vascular AAA Stent-Graft System to the desired location within the aorta, and evaluate the ability of the TriVascular AAA Stent-Graft to exclude the abdominal aortic aneurysm.

Inclusion Criteria:

• Male or infertile female
• Have signed an informed consent form.
• Are considered an appropriate candidate for open surgical repair of an abdominal aortic aneurysm.
• at least one of the following: Abdominal aortic aneurysm >= 4.5 cm in diameter; aneurysm has increased in size by 0.5cm in last 6 months; maximum diameter of aneurysm exceeds 1.5 times the transverse dimension of an adjacent normal aortic segment; saccular aneurysm larger than 3 cm.
• Have patent iliac or femoral arteries that allow endovascular access to the aneurysmal site with a 17F Delivery Catheter.

Exclusion Criteria:

• A dissecting, acutely ruptured, or leaking aneurysm, or an acute vascular injury due to trauma.
• A need for emergent surgery.
• contraindication to undergoing angiography.
• A Thoracic aortic aneurysm that requires treatment.
• Presence of thrombus or atheroma in proximal aortic neck covering > 50% of the endoluminal surface.
• Presence of diffuse atherosclerotic disease in either common iliac artery that reduces the iliac artery diameter to <7mm.
• Congenital abnormalities in which the placement of the stent-graft will cause occlusion of major arterial flow. Such abnormalities should be evaluated(e.g. angiography or CT) prior to treatment.
• Unstable angina
• Morbid obesity or other clinical conditions that severely inhibit x-ray visualization of the aorta.
• Connective tissue disease (e.g., Marfan's or Ehlers-Danlos syndrome.)
• Hypercoagulable state.
• Contraindication for anticoagulation.
• Acute renal failure.
• Active systemic infection.
• less than 18 years of age.
• Life expectancy less than 1 year.
• Current, or anticipated participation within 1 year, in another research study involving an investigational device or new drug (with the exception of participation in the Lifeline Registry of Endovascular Therapy).
• Other medical, social, or psychological issues that in the opinion of the investigator preclude them from receiving this treatment, and the procedures and evaluations pre- and post-treatment.