Evaluation of the Endurant stent graft under instructions for use vs off-label conditions for endovascular aortic aneurysm repair.

BACKGROUND: This study evaluated the early and intermediate results of endovascular aortic aneurysm repair (EVAR) using the Endurant stent graft (Medtronic Cardiovascular, Santa Rosa, Calif) in patients treated according to device-specific instructions for use (IFU) for the proximal aortic neck compared with those obtained in patients treated in an off-label (OL) situation.

METHODS: Between November 2007 and March 2010, 177 consecutive patients with abdominal aortic aneurysms (AAAs) were treated with the Endurant stent graft at our centers. The IFU for the Endurant stent graft included a proximal neck of 15 mm in length and <75° of angulation or 10 mm of neck length and <60° of angulation. The 121 patients (68.4%) operated on according to IFU were compared with 56 (31.6%) who underwent EVAR in OL circumstances to evaluate significant differences in demographics, intraoperative technical factors, and early (30 days) and intermediate outcomes (1 year).

RESULTS: Significantly more patients were aged >80 years in the OL group (37.5% vs 19%, P = .008), and they also had larger aneurysms (59 ± 10.6 vs 55.9 ± 10.8 mm, P = .05) and required a longer procedure time (69.3 ± 27.2 vs 60.8 ± 20.4 minutes, P = .02). At 30 days, the risk of type I endoleak was higher in the OL group (2 patients, 3.6% vs 0 in IFU), but this did not reach statistical significance (P = .09). The two groups were similar in rates of perioperative mortality, major morbidity, technical success, clinical success, complications, and reinterventions. At 1 year, there were no differences between the two groups in survival, freedom from any device-related reinterventions, and freedom from graft thrombosis. Estimated 1-year freedom from type I endoleak was 100% in the IFU group vs 93.3% in the OL group (P = .01).

CONCLUSIONS: In patients with both normal and complex anatomy of the proximal aortic neck, the Endurant stent graft obtained acceptable results, with no difference in survival, morbidity, or reinterventions. However, there was a greater risk of type I endoleak when OL indications were applied. Longer term follow-up is required to evaluate the effectiveness of this endograft in preventing late aneurysm-related complications.