Impact of the Repositionable C3 Excluder System on the Endovascular Treatment of Abdominal Aortic Aneurysms With Unfavorable Neck Anatomy

Abstract

Purpose: To analyze the midterm clinical outcomes among patients with favorable and unfavorable neck morphology for endovascular aneurysm repair (EVAR), specifically the impact of the repositionable C3 Excluder stent-graft on type I endoleak in patients with unfavorable neck. Methods: A retrospective review was conducted of 249 patients (mean age 74.3 years; 241 men) who underwent successful EVAR from January 2000 to December 2014 using either the traditional Excluder (n=140) or the C3 repositionable system (n=109). Unfavorable proximal aortic neck anatomy was defined by length <15 mm, angulation >60°, >50% circumferential thrombus, or >50% neck calcification. By these criteria, unfavorable neck anatomy was present in 71 (28.5%) patients (41 traditional Excluder and 30 C3 Excluder). The main endpoint was the incidence of type Ia endoleak and the need for a proximal cuff according to the type of neck anatomy. Comparisons between groups are reported as the odds ratio (OR) and 95% confidence interval (CI). Results: A proximal extension cuff for type Ia endoleak was needed in 4 (2.2%) patients with favorable neck anatomy compared to 7 (9.9%) patients with unfavorable neck (OR 4.76, 95% CI 1.3 to 16.8, p=0.014). Among the patients with unfavorable neck, a proximal cuff was implanted in 6/41 (14.6%) traditional Excluder stent-grafts vs 1/30 (3.3%) in the C3 Excluder group (OR 4.39, 95% CI 0.55 to 34.58, p=0.23). Median follow-up was 30.5 and 38 months for favorable vs unfavorable neck groups, respectively (p=0.29). Only 1 case of type Ia endoleak was registered at 6.5 years’ follow-up (traditional Excluder), with no device migration. Conclusion: Both Excluder stent-grafts provide good midterm clinical outcomes after EVAR in patients with unfavorable neck anatomy. Investigation of a larger cohort will be needed to identify if the C3 Excluder device offers any improvement over the traditional Excluder in terms of freedom from endoleaks.