Impact of Morphological Factors on the Future Growth of Unruptured Posterior Communicating Artery Aneurysms

Abstract

No previous study has established the factors associated with intracranial aneurysm growth using imaging data obtained before the appearance of morphological changes. Therefore, we investigated the factors related to future aneurysm growth in posterior communicating artery (Pcom) aneurysms. Using a longitudinal database of intracranial aneurysm cases, we reviewed the findings for consecutive patients with unruptured Pcom aneurysms admitted to our institute from 2012 to 2021. Magnetic resonance images obtained over time were used to evaluate aneurysm growth. Aneurysms showing growth over time (group G) and unchanged aneurysms (group U) were compared in terms of background data and morphological factors. 93 Pcom aneurysms (group G: 25 aneurysms, 25%; group U: 68 aneurysms, 75%) were eligible for the present study. Six aneurysm rupture events occurred in group G (24%). Among morphological factors, Pcom diameter (1.2±0.3mm vs. 0.8±0.7mm, P<0.01), bleb formation (group G: 39% vs. group U: 10%; odds ratio, 5.6; P=0.01), and the lateral projection of the dome (group G: 52% vs. group U: 13%; odds ratio, 3.2; P=0.023) were significantly different between the 2 groups. The sensitivity and specificity of a cutoff Pcom diameter of 0.73mm for predicting enlargement were 96% and 53%, respectively. Pcom diameter, bleb formation, and lateral dome projection were associated with growth of Pcom aneurysms. Aneurysms with these risk factors require careful follow-up imaging, which may facilitate early detection of aneurysm growth and prevention of rupture through therapeutic interventions.