Postoperative surveillance
Postoperative evaluation consisted of clinical and radiological assessment at discharge, 1 month, 6 months, 12 months and annually thereafter. Both computed tomographic examination and Doppler ultrasonography were performed at 1 month. If there were no type 1 or 3 endoleaks at first evaluation, subsequent assessments of endoleak and sac diameters were performed only by Doppler ultrasonography. Type 2 endoleaks were also assessed only by Doppler ultrasonography as they are accepted as benign endoleaks in the absence of sac enlargement. If there was suspicion of sac enlargement at ultrasonographic examination, this finding was checked by tomography. Sac enlargement was defined as minimum of 5 mm enlargement compared to the preoperative diameter. Contrast angiography was performed at the hybrid room only when a secondary intervention was needed.