The Endurant Stent-Graft U.S. Clinical Trial: 2-Year AAA Diameter Outcomes Are Predicted by 6-Month Volume Outcomes

This study reports the 2-year diameter and volume data for abdominal aortic aneurysms (AAAs) treated in the U.S. pivotal clinical trial of the Endurant Stent Graft System. From April 2008 to May 2009, 150 patients were treated with the Endurant stent graft as part of a prospective multicenter trial. The main inclusion criteria were AAA diameter >5 cm, neck length ≥10 mm, and neck angulation <60°. A core laboratory reviewed all imaging. Expansion was defined as >5 mm diameter or >5% by 3-dimenional volume. Stent graft implant was successful in 149 of 150 patients. The 6-month volume results were nearly identical to the 24-month diameter results, and all AAAs identified with expansion by diameter at 24 months had expansion by volume criteria (but not diameter) at 6 and 12 months. Change in AAA size was more likely to be identified by volume at all time points, with <13% of AAAs classified as “no change” by volume criteria at 1 and 2 years (P < .05). Most AAAs classified as “no change” by diameter criteria were shrinking by volume criteria. Secondary intervention for endoleak occurred in five patients, all suspected type II endoleak. All were identified as expanding earlier by volume, including two ultimately identified to be a type I endoleak. There were no ruptures or aneurysm-related deaths. Midterm results of the Endurant pivotal trial are good, with low expansion rates at 2 years, even by volume criteria. Three-dimensional volume detects aneurysm shrinkage and expansion on average 18 months sooner than diameter, allowing for earlier reassurance in most patients and earlier intervention in the small minority who need it. TableAAA outcomes over timeOutcomeDecrease (%)No change (%)Increase (%)Diameter 6 mon31690 12 mon47530 24 mon63352Volume 6 mon63344 12 mon79137 24 mon781210 Open table in a new tab