Final results of the Endurant Stent Graft System in the United States regulatory trial

Objective To report the 5-year outcomes from the Endurant Stent Graft System in the U.S. regulatory trial (bifurcated Endurant; Medtronic Santa Rosa, Calif). Methods The study was a prospective, multicenter, regulatory trial performed at 26 U.S. sites. From June 2008 to April 2009, 150 patients with abdominal aortic aneurysms (AAAs) were treated with the Endurant bifurcated graft. The main inclusion criteria included AAA diameter >5 cm (or 4-5 cm in diameter where the size increased more than 5 mm within the previous 6 months), neck length ≥10 mm, and neck angulation ≤60 degrees. A clinical events committee adjudicated all untoward events, and a core laboratory reviewed available imaging at 1, 6, 12, 24, and 60 months. Outcomes were compared with the Talent enhanced Low Profile System (eLPS) study for regulatory purposes. At 5 years, clinical follow-up was available on 94% and imaging on 87% of 101 eligible patients. Results At 5 years, all-cause mortality estimate by Kaplan-Meier was 17.7%, and freedom from aneurysm-related mortality was 99.2%. One aneurysm-related mortality was noted in a patient that refused treatment for a type I endoleak and died in year 4 from rupture. There were no endograft migrations, fractures, or open conversions. At 5 years, endoleaks were identified in 7/83 patients (8.4%) and included six type II endoleaks and one of indeterminate origin. Maximum AAA diameter decreased by more than 5 mm in 53/83 patients (63.9%), remained stable in 25/83 (30.1%), and increased >5 mm in 5/83 (6.0%). Eighteen AAA-related secondary interventions were required in 15 patients (11%): 12 for endoleak management, 4 for limb occlusions, 1 for stenosis, and 1 for thromboembolism. Four of 5 limb occlusions reported were in the first 6 months. Survival and reintervention rates were better than the Talent eLPS study, which was conducted under similar inclusion exclusion criteria. Conclusions The 5-year outcomes of the Endurant Stent Graft System in the U.S. regulatory trial continue to be positive. The device appears to be durable with limited adverse events through 5 years. Comparison with an older generation device suggests improving outcomes with newer devices.