Comparative imaging study between ruptured and large, unruptured abdominal aortic aneurysms

BACKGROUND: The aim of this study is to determine potential clinical and computed tomography (CT) imaging predictors for abdominal aortic aneurysm (AAA) rupture based on a comparative analysis of patients presenting with large (>6.5 cm diameter) unruptured AAA (uAAA) and patients presenting with ruptured AAA (rAAA) respectively.METHODS: Consecutive patients presenting with large unruptured or rAAA and having undergone a contrast-enhanced CT at admission between January 2005 and June 2019 were included. Patients’ demographics and CT-imaging characteristics were collected from the institutional electronic medical records. Both patient groups were compared using Fisher’s Exact Test for categorical variables and the Mann-Whitney U Test for continuous variables.RESULTS: We included 101 patients, of which 57 patients presenting with a rAAA and 44 patients with a large, uAAA. Patients in the large, uAAA group were younger, mean age of 76 years vs. 83 years (P<0.001), had less coronary artery disease (47.6% vs. 72.5%; P=0.026) and had a lower left common iliac artery to maximum aneurysm diameter ratio (0.15 vs. 0.18; P=0.034), a lower sum of right + left common iliac artery to maximum aneurysm diameter ratio (0.31 vs. 0.39; P=0.028) and a lower infrarenal neck to maximum aneurysm diameter ratio (0.29 vs. 0.35; P=0.039).CONCLUSIONS: Patients with large, uAAA’s were younger with less coronary artery disease and presented with lower ratio of right + left common iliac artery to maximum aneurysm diameter as well as a lower ratio of infrarenal neck to maximum aneurysm diameter on CT-imaging compared to patients with rAAA.