Aneurysmal subarachnoid hemorrhage in a patient with bilateral A(1) fenestrations associated with an azygos anterior cerebral artery - Case report and literature review

Fenestration of the proximal anterior cerebral artery (A(1) segment) is a rare occurrence. This vascular anomaly is often associated with aneurysms and other abnormalities. The current article describes the case of a 33-year-old man who presented with a subarachnoid hemorrhage secondary to a ruptured aneurysm originating from the proximal end of an A, fenestration. This patient also had a contralateral A, fenestration as well as an azygos anterior cerebral artery. This is the first report of such an unusual vascular anatomy. The literature is reviewed and possible embryological mechanisms are discussed.