[Dural arteriovenous fistula manifesting as subarachnoid hemorrhage at the craniocervical junction. A case report].

A 65-year-old man suddenly developed severe headache, vertigo, and sensory disturbance of the right side. On the CT, a high density round mass was identified in the dorsal portion of the pons. The patient's level of consciousness decreased one hour later. A repeat CT showed diffuse subarachnoid hemorrhage and hydrocephalus. Angiography demonstrated a dural arteriovenous fistula (DAVF) at the craniocervical junction. The main feeding artery was the left C2 radicular artery, and the fistula was drained by a leptomeningeal vein that proceeded upward and had a venous ectasia in its distal portion. Transarterial embolization could not be performed because the feeding artery could not be cannulated using a microcatheter. 3D-CT angiography showed a single draining vein at the anterior portion of the left vertebral artery. Four weeks later, ventricular drainage was instituted following surgical disruption of the arteriovenous fistula's draining vein. Postoperative angiography demonstrated complete obliteration. In the present case, surgical clipping of the draining vein was safe and effective; surgical resection of the DAVF or cautery of the surrounding dura was not necessary. Intraoperative digital subtraction angiography (DSA) was as useful as the Doppler technique.