An abdominal aortic aneurysm rupture risk score: a pilot study for combining precise aortic measurements and clinical factors

Abstract

ObjectiveCurrent screening and management for abdominal aortic aneurysms (AAAs) are based on maximal aortic diameter criteria. This study sought to compare anatomic and clinical factors between ruptured and intact AAAs to identify predictors of rupture. MethodsPatients treated for AAAs at Thomas Jefferson University Hospital from 2010 to 2021 were reviewed from intact AAAs (iAAAs), ruptured AAAs (rAAAs), and no aortic pathology (NP) groups. Preoperative computed tomography angiography (CTA) studies were retrospectively measured with Aquarius iNtuition (TeraRecon Inc). Maximal diameter, length, mural thrombus volume (MTV), and calcification volume were measured from the lowest renal artery to the femoral artery. A rupture risk score was calculated using AAA diameter (1 point), percent ≥MTV 50% (1 point), number of antihypertensive agents <2 (1 point), not on cholesterol-lowering medication (1 point), and active smoking (1 point) for a 5-point total score. ResultsCTAs from 48 patients (age, 69.5 ± 8.1 years; 87.5% male) were measured (23 iAAAs, 15 rAAAs, and 10 controls). When compared with iAAAs, the maximal AAA diameter (rAAA, 7.71 cm; iAAA, 6.02 cm; P = .005) and %MTV (rAAA, 66.1%; iAAA, 45.3%; P = .0001) were greater in patients with rAAAs. Mean AAA rupture risk score was greater in patients with rAAAs than those with iAAAs (rAAA, 3.40 ± 1.12; iAAA, 1.78 ± 1.44; P < .001) with 100% of rAAAs and 47.8% of iAAAs having a score 2 or greater. ConclusionsThis study demonstrates that AAA diameter, percent MTV, blood pressure control, and active smoking are significant risk factors for AAA rupture. Patients with multiple risk factors (risk score ≥2) were more likely to rupture and should be considered high risk.