Risk Factors of Middle Cerebral Artery Aneurysm.

According to the current view, cerebral aneurysms are acquired degenerative lesions resulting from hemodynamic stress. This single-center case-control study will be carried out at the Department of Neurosurgery, Regional Hospital in Sosnowiec, Medical University of Silesia in Katowice, Poland between June 2015 and June 2017. The aim of the study is to determine morphometric and hemodynamic parameters of aneurysmal and non-aneurysmal middle cerebral artery (MCA) bifurcations and to analyze their relationship with aneurysm formation. A minimum of 75 cases and 75 age- and sex-matched controls will be required for the study. Characteristics of the MCA bifurcations will be determined with computed tomography angiography (CTA) and transcranial color-coded sonography (TCCS). The following variables will be evaluated as potential risk factors for MCA aneurysm formation: radii and cross-sectional area of the main MCA trunk and its branches, tortuosity of MCA trunk, asymmetry ratio, area ratio, the angle between the post-bifurcation branches, the angles between the MCA trunk and the larger and smaller branch, volume flow rate, mean flow velocity and pulsatility index of the MCA. All morphometric and hemodynamic parameters will be assessed as potential risk factors for MCA aneurysm formation.