Fenestrated anterior cerebral artery with associated arterial anomalies. Case reports and literature review.

Fenestration of the A2 segment is extremely rare. Cerebrovascular fenestration may be associated with an increased incidence of cerebral aneurysm and other vascular anomalies. Two case reports are presented which identify a fenestration of the A2 segment and other normal variations of the intra-cerebral circulation. A review of the literature has been undertaken to determine the prevalence and embryology of anterior cerebral artery fenestrations, their clinical significance and the association with aneurysm formation and other intracranial vascular anomalies.