Giant fusiform basilar artery aneurysm: endovascular treatment by flow reversal in the basilar artery.

We report a patient presenting with subarachnoid haemorrhage due to rupture of a giant fusiform aneurysm of the proximal basilar artery. The aneurysm was successfully treated by reversing blood flow in the basilar artery by balloon occlusions of both vertebral arteries proximal to the posterior inferior cerebellar artery origins. Substantial thrombosis and regression of the aneurysm was evident 4 months later.