ABSTRACT
Fenestrated basilar artery is a uncommon congenital anomaly. It is seen in approximately 0.3 to 5.26% of autopsy series, but only in 0.1 to 1.9% of angiography series. Because the fenestrated basilar artery is a defect or weakness of muscular and internal elastic lamina, incidence of fenestration of the basilar artery when a vertebrobasilar artery aneurysm is present is reported to be 35.5%. We experienced one case of fenestrated basilar artery associated with multiple aneurysms(fenestrated basilar artery, basilar tip, left posterior communicating artery). We operated the basilar tip aneurysm and the posterior communicating artery aneurysm. Although we didn't operate the fenestrated basilar artery aneurysm, we report one case with review of literature in order to improve the operative result of the fenestrated basilar artery aneurysm.