Connection between a dural artery and a dural vein in a dural arteriovenous fistula of the cranial vault.

A 41-year-old man presented with consciousness disturbance and right hemiparesis. Computed tomography showed a hematoma in the frontal lobe. Left carotid angiography showed a dural arteriovenous fistula (AVF) located in the cranial vault, supplied by the left middle meningeal artery, and drained directly into the cortical vein adjacent to the superior sagittal sinus. Emergency decompressive craniectomy and evacuation of the intracerebral hematoma were performed. A red vein was found on the cortex but the location of the arteriovenous shunt was not clear due to severe brain swelling. Two months later, cranioplasty was performed and a part of the dura mater, expected to have been affected by the dural AVF, was resected. Histological examination disclosed thickening of the intima of the middle meningeal artery and a few small veins around this artery. The fistula was clearly demonstrated between the dural artery and the dural vein. The non-sinal type of dural AVF may originate in similar arteriovenous connections to the sinal type.