Fatal intracranial hemorrhage after balloon occlusion of an extracranial vertebral arteriovenous fistula. Case report.

A patient is presented who developed a fatal hemorrhage immediately after balloon occlusion of an extracranial vertebral arteriovenous fistula. The fistula was associated with marked retrograde flow not only from the contralateral vertebral artery but also from the carotid artery system through the posterior communicating artery and the basilar artery. The bleeding appeared to be caused by acute hemodynamic effects following abrupt occlusion of the long-standing fistula. A gradual staged occlusion or trapping procedure should be considered for the treatment of such vertebral arteriovenous fistulae.