Abstract WP121: Patient- and Aneurysm-specific Predictors of Intracranial Aneurysm Growth in a Longitudinally-followed Population

Abstract

Introduction: Intracranial aneurysms (IA) which occur in adults are assumed to undergo growth at some point during their natural history. However, the factors which may contribute to IA growth in certain individuals are largely unresolved, with significant variation between previous studies. In this study we examine 520 IA which were longitudinally followed by 3D CT images. We examined 21 patient- and aneurysm-specific factors (including patient medical history, aneurysm size, location and multiply) with potential relevance to IA growth. Hypothesis: Patient- and aneurysm-specific characteristics may determine whether an IA is likely to grow. Methods: IA were diagnosed between 2005-2015 and were longitudinally followed with medical imaging (CTA). Univariate logistic regression with calculation of odds ratios (OR) and 95% confidence intervals (95% CI) were determined using univariate logistic regression with a growth threshold defined as an IA size increase greater than 0.6 mm. Results: Every 1 mm increase in initial IA size was associated with a significant 1.09-fold increase in risk of growth (95% CI: 1.04-1.15; P=0.001). Compared to patients with single IA, in patients with multiple IA, IA were 2.43-fold more likely to grow (95% CI: 1.36-4.35; P=0.003). A diagnosis of hypertension was found to associate with a borderline significant 1.76-fold increased risk of IA growth compared to patients who did not have hypertension (95% CI: 0.93-3.32; P=0.082). Conclusions: Previous meta-analyses have found predictors of IA growth to be extremely heterogeneous, exacerbated by the relatively small sample size of many of the included studies. In this context, our finding of IA size to be a significant predictor of growth and hypertension to be borderline significant in a relatively large set of cases contributes valuable additional data to understanding IA growth.