Midterm Results of Endovascular Aneurysm Repair Using the Endurant Stent-Graft According to the Instructions for Use vs. Off-Label Conditions

Purpose: To compare the midterm results in patients treated with the Endurant stent-graft according to device-specific instructions for use (IFU) vs. those treated in an off-label (OL) situation. Methods: Between November 2007 and March 2010, 177 patients (161 men; mean age 73.7 years) with abdominal aortic aneurysm were treated with the Endurant stent-graft at 2 European centers. Patients operated on according to the IFU (121, 68.4%) were compared with those who underwent endovascular aneurysm repair in OL circumstances (56, 31.6%) to evaluate estimated 5-year survival, freedom from any device-related reinterventions, freedom from graft thrombosis, and freedom from type I endoleak. Univariate and multivariate analyses were performed to identify independent predictors of poor outcomes in the OL group. Results: Mean follow-up was 31.2 months (range 1-65). At 5 years, there were no differences in terms of survival (67.9% IFU vs. 54.1% OL, p=0.3), freedom from any device-related reintervention (91.2% IFU vs. 92.4% OL, p=0.8), or freedom from graft thrombosis (97.5% IFU vs. 92.7% OL, p=0.3). Estimated 5-year freedom from type I endoleak was significantly better in the IFU group than in OL (100% vs. 96.2%, respectively; p=0.03). In the OL group, multivariate analysis showed that female sex and coronary artery disease were independent predictors of poor survival. Conclusion: Off-label use of the Endurant stent-graft was associated with a greater but acceptable risk of type I endoleak. Otherwise, there was no difference between the IFU and off-label groups as regards survival, graft thrombosis, or reintervention.