Evaluation of Potential Outcome Predictors in Type II Endoleak: A Retrospective Study With CT Angiography Feature Analysis

Abstract

The purpose of this study is to investigate which CT features of type II endoleaks following abdominal aortic aneurysm (AAA) endoluminal stent-graft repair can be used to predict clinical outcome. We retrospectively identified 59 patients with type II endoleak after endovascular repair of an AAA with CT of the abdomen and pelvis. Patients were stratified into two groups: those who did (n = 23) and those who did not (n = 35) require reintervention. CT characteristics of type II endoleaks were recorded and correlated with the clinical outcome. The CT features showing the strongest association with the clinical outcome were the transverse diameter of the endoleak cavity (mean, 1.13 cm in the nonreintervention group vs 1.85 cm in the reintervention group; p = 0.007) and the maximum diameter of the vessel communicating with the endoleak (0.34 vs 0.40 cm; p = 0.046). The transverse diameter of the endoleak cavity on arterial phase imaging had the greatest predictive capability, with an area under the receiver operating characteristic curve of 0.74. A transverse diameter greater than 1.42 cm had a positive predictive value of 0.71 and a negative predictive value of 0.82. The anteroposterior diameter, location, and heterogeneity of the endoleak cavity and the number of patent communicating vessels did not correlate well with clinical outcome. The correlation between endoleak cavity measurements and clinical outcome was independent of the aneurysm size. There are identifiable CT features associated with the clinical outcome of patients with type II endoleak that have moderate predictive capabilities.