Device migration and endoleaks were very infrequent after treatment with the Zenith AAA Endovascular Graft. However, endograft oversizing of >30% was associated with an approximately 14-fold increase in device migration (>5 mm) at 12 months and with a approximately 16-fold increased risk of AAA expansion at 24 months. Although further follow-up will be essential to assess whether these early associations continue, avoidance of excessive endograft oversizing is recommended.

The intermediate-term (24-month) results of the 30 patients in this multicenter study are concordant with previous single-center studies and support the concept that placement of fenestrated endovascular grafts is safe and effective at centers with experience in endovascular repair and renal/mesenteric stent placement.

Aortic neck angulation appears to be an important determinant of outcome after EAAA repair. Although patients with mild angulation (<40 degrees) had favorable outcomes in this series, those with moderate (40 to 59 degrees) or severe angulation (>or=60 degrees) had a 54% to 70% risk of one or more adverse events. Importantly, these outcomes occurred in spite of an adequate length (>2 cm) of proximal aortic neck. On the basis of these data, great caution should be exercised in recommending EAAA repair for patients with aortic neck angulation >or=40 degrees.

The Zenith AAA Endovascular Graft is safe and effective for treatment of infrarenal AAAs. The high likelihood of decrease in aneurysm size provides evidence that treatment of aneurysms with this device reverses the natural history of aneurysmal disease. The importance of long-term follow-up is underscored by the small but defined incidence of barb separation and the potential for unforeseen failure modes.

Absence of endoleak at 30 and 365 days predicted greatly improved long-term freedom from ARM compared with early endoleak. A new EVAR surveillance regimen is recommended that modulates the intensity and frequency of postoperative imaging based on these early outcomes. In patients without early endoleak, the 6-month surveillance is eliminated, and aortic ultrasound is suggested for long-term surveillance >1 year. In most patients, this reduced surveillance regimen would be appropriate and could improve patient safety by reducing the cumulative deleterious effects of intravenous contrast and radiation exposure while also reducing health care costs. These subjective recommendations would be ideally validated in a randomized, prospective trial.