Preoperative Mural Thrombus Volume Ratio Predicts Aneurysm Enlargement in Type 2 Endoleak after Endovascular Aortic...

This study aimed to identify anatomical predictors of aneurysm enlargement in patients with lumbar artery (LA)-related type 2 endoleak (T2EL) after endovascular aortic repair (EVAR).

This retrospective observational cohort study included 59 patients with infrarenal abdominal aortic aneurysms who developed T2EL caused exclusively by LAs after EVAR between January 2019 and July 2024. Computed tomography-based anatomical parameters, including mural thrombus volume ratio, calcified volume ratio, aneurysm diameter, and LA anatomy, were analyzed.

During a median follow-up of 33 months, aneurysm enlargement occurred in 9 patients (15.3%). Patients with aneurysm enlargement had a significantly lower mural thrombus volume ratio (p <0.001). Female sex (hazard ratio [HR], 0.23; 95% confidence interval [CI], 0.06-0.84; p = 0.026) and mural thrombus volume ratio (HR, 0.88 per 1% increase; 95% CI, 0.80-0.96; p = 0.003) were significantly associated with aneurysm enlargement, whereas LA anatomy was not. Receiver operating characteristic analysis identified an optimal cutoff value of 29.2% (area under the curve, 0.82).

A low preoperative mural thrombus volume ratio was associated with aneurysm enlargement in patients with LA-related T2EL after EVAR. This parameter may serve as a practical imaging biomarker to support selective consideration of preemptive embolization.