Anaesthesia for cerebral arteriovenous malformations in children

Between 1966 and 1982, 46 patients underwent a total of 50 craniotomies for exploration and excision of cerebral arteriovenous malformations (AVMs) at The Hospital for Sick Children, Toronto. Thirty-three of these patients presented with intracranial haemorrhage, 13 of whom required emergency operations. Thirteen patients underwent elective surgery after investigation of a variety of medical complaints. In most cases, anesthesia was induced with thiopentone followed by a muscle relaxant to facilitate intubation. Anaesthesia was maintained with nitrous oxide and oxygen, a muscle relaxant, halothane and/or an intravenous narcotic, and positive pressure ventilation. In 60 percent of patients, blood loss was less than 20 per cent of estimated blood volume (EBV) although four children lost more than 50 per cent of their EBV. There were no deaths during operation. Controlled hypotension was employed in 30 operations to improve operating conditions during excision of deep-seated AVMs. Blood loss was similar in the non-hypotensive group, but these procedures tended to be of shorter duration. The advantages of various hypotensive techniques in children undergoing operations for cerebral AVMs are discussed and current anaesthetic management at The Hospital for Sick Children is described.