The Impact of Endograft Selection on Outcomes Following Treatment Outside of Instructions for Use (IFU) in Endovascular Abdominal Aortic Aneurysm Repair (EVAR)

Background Endovascular aneurysm repair (EVAR) has become the treatment modality of choice in patients with abdominal aortic aneurysms. This has resulted in endograft utilization within instructions for use (IFU) and in cases with proximal neck anatomy outside of IFU. Purpose To identify whether graft selection influences outcomes following EVAR outside of IFU. Methodology A retrospective analysis was conducted from previously published data for 636 patients, collated from the Endurant Stent Graft Natural Selection Global Post-Market Registry (ENGAGE) and the Global Registry for Endovascular Aortic Treatment (GREAT). Patients were recruited into the ENGAGE registry between 2009 and 2011 and into the GREAT registry between August 2010 and October 2016. In ENGAGE, they received the Medtronic Endurant stent graft (Medtronic Vascular Inc, Dublin, Ireland) for infrarenal AAA repair while patients analyzed in GREAT received the Gore Excluder stent-graft (W. L. Gore & Associates, Flagstaff, Arizona). Analyses were performed to evaluate all-cause mortality, aneurysm-related mortality, endoleak occurrence, and surgical reintervention rates between the two cohorts. Results Of the 636 patients, 225 were from ENGAGE (mean age 73 years) and 411 were from GREAT (mean age 75 years). 17.8% were treated outside of IFU in the ENGAGE registry, while 12.4% were treated outside IFU in the GREAT cohort. Five-year freedom from all-cause mortality was similar in both cohorts (65.6% vs. 63.8%). The rate of type IA endoleak development was lower in the Excluder cohort, although this may have been impacted by the fact that only endoleaks that underwent reintervention were recorded within GREAT analysis (Endurant 10.6% vs. Excluder 7.0%). The reintervention rate was 16% at five years following the Endurant aortic graft while it was 13.3% at five years with the Excluder. Conclusion Treatment outside of IFU, be it with a suprarenal or an infrarenal fixation device, is associated with worse outcomes. This analysis reinforces the importance of the consideration of either fenestrated or open repair in those aneurysms that fail to satisfy IFU while endovascular repair in such a setting should be reserved as a last resort strategy.