[Supratentorial extradural hematomas following posterior fossa craniectomy (author's transl)].

Five cases of the supratentorial extradural hematomas secondary to the posterior fossa craniectomy were reported. The site of the hematoma was far from the operative field and two cases showed acute course and three were rather mild. The symptoms of this complication were the unsuspected sensorium disturbance, anisocoria and the non-functioning ventricular drainage. Two cases died of this complication and two were severely disabled. The mechanism of this complication is not clearly understood. The lowering of the ventricular pressure by the ventricular tap during the operation may play significant role in the formation of the extradural hematoma. The younger age of the cases and the long history of increased intracranial pressure were stressed in the literature. The significance of the management of the ventricular pressure during the operation was emphasized. The prevention is the best treatment.