IP041 - Predictive Parameters for Rupture in Abdominal Aortic Aneurysms

Objectives: Current screening and management for abdominal aortic aneurysms (AAA) are based on maximal aortic diameter criteria. This study sought to compare aortic measurements between ruptured and intact AAAs to identify prognostic markers for rupture.

Methods: Patients treated for AAA at Thomas Jefferson University Hospital from 2014-2021 were randomly selected from intact AAA (iAAA), ruptured AAA (rAAA), and no aortic pathology (NP) groups. Preoperative computed tomography angiography (CTA) studies were retrospectively measured with Aquarius iNtuition (Terarecon Inc., CA, USA). Maximal diameter, length, mural thrombus volume (MTV), and Hounsfield calcification were measured from the lowest renal artery to the femoral artery. The aortic-height index (AHI = max AAA diameter + length / height) was calculated to control for height. One-way ANOVAs followed by Tukey’s multiple comparison tests, and Pearson’s correlation were performed using GraphPad Prism version 9.3.1.

Results: CTAs from 45 patients (age 69.40 ± 8.28, 86.6% male) were measured in iAAA (19, 42.2%), rAAA (16, 35.6%), and NP (10, 22.2%) groups. When compared to iAAA, the maximal AAA diameter (7.71 cm vs 6.19 cm, p=0.022) and MTV (180.8 cm3 vs 91.79 cm3, p=0.0323, Fig.1) was larger in rAAA patients. Infrarenal aortic length was positively correlated with AAA diameter (r(43)=.66, p<.0001, Fig.2), and increased in AAA compared to NP (rAAA 12.89 cm, iAAA 13.03 cm, NP 9.75 cm, p< 0.0001). AHI was elevated in rAAA compared to iAAA patients (4.50 cm/m vs 3.43 cm/m, p=0.0102, Fig.1). All other parameters did not differ between rAAA and iAAA.

Conclusions: Our study demonstrates that AAA diameter, MTV, and AHI are significant predictors of rupture in AAA. Additionally, infrarenal aortic length may be a viable prognostic marker for AAA vessel wall strength, warranting further investigation. These results will assist in identifying high-risk patients for rupture.