Sixteen-Year Survival after Endovascular Abdominal Aortic Aneurysm Repair with the Zenith Stent Graft

Abstract

Introduction - Although endovascular aneurysm repair (EVAR) is in widespread use, truly long-term data is still lacking. This study characterizes our sixteen year experience of EVAR using the Zenith stent graft in a single academic center. Methods - Between 2000 and 2010, 282 patients with abdominal aortic aneurysm (AAA) underwent elective EVAR using the Zenith stent graft (Cook Inc. Bloomington, Ind). Patients were annually monitored thereafter. Primary outcomes were overall and AAA-rupture free survival. Secondary outcomes were survival from graft-related complications and re-interventions. Results - Mean age was 75 years (range, 49- 92 years) and mean aneurysm diameter 61mm (range, 40-110mm) at the time of the initial treatment. The mean follow-up was 79 months (range, 0-201 months). The overall survival was 93%, 61%, 25% and 9% at 1, 5, 10 and 16 years. Even for those ≥80 years, the survival was 46% at 5 years. Five AAA ruptures occurred during the follow-up, four of which were fatal. Consequently, cumulative AAA-rupture free survival was 100%, 99%, 97% and 97% at 1, 5, 10 and 16 years. Freedom from any stent graft related complications was 68%, 58%, 54%, 52%, and from graft-related re-interventions 95%, 80%, 73%, 70% at 1, 5, 10 and 16 years, respectively. Only five (1.8%) late conversions to open repair were required during the follow-up. Aneurysm sac shrinkage ≥5mm was seen in 60% of the cases with the mean decrease of 18.5mm in maximum diameter. Conclusion - Fatal AAA rupture after EVAR is a rare phenomenon and patients eventually die from natural causes. Even octo-and nonagenarians seem to tolerate the procedure well as almost half of the patients are still alive at five years. The number of graft-related complications is relatively high, but according to our findings, they don’t always require re-intervention and can safely be followed. New complications keep appearing years after the initial procedure thus suggesting the life-long surveillance as mandatory.