Circle of Willis Variants and Intracranial Aneurysm Risk: Evidence from an Autopsy-Based Study

Abstract

This study investigates the correlation between anatomical variants of the Circle of Willis (CoW) and the presence of intracranial aneurysms (IcAs), a relationship insufficiently addressed in current literature. We conducted a 12-year retrospective observational study on 221 adult autopsied patients admitted to the “Prof. Dr. N. Oblu” Emergency Clinical Hospital in Iași, Romania. Demographic data, aneurysm morphology (location, diameter), and CoW anatomical variants were analyzed. IcAs were found in 29 cases (13.12%), most frequently located at the Anterior Communicating Artery (55.2%), with a majority measuring under 10 mm in diameter. A strong association was observed between IcAs and atypical CoW configurations (96.55%), particularly when three or four anatomical variants coexisted. No gender predisposition was identified. The mean age of patients increased with aneurysm size, yet larger aneurysms were less often associated with progression to death. Our findings suggest that the presence of multiple CoW variants significantly increases the likelihood of developing IcAs. These results may enhance prognosis and support clinical decision-making frameworks for managing cerebral aneurysms.