Anesthetic management of arteriovenous malformation: a case report

This case illustrates the anesthetic management of radiographically assisted embolization and surgical excision of a large arteriovenous malformation (AVM). Excision resulted in significant blood loss and cerebral edema. This prompted the use of cerebral protection and induced hypotension. The patient was kept in a barbiturate coma postoperatively. On emergence from the barbiturates, the patient demonstrated elevated intracranial pressure and resolving deficits. She was discharged 3 weeks after surgery for rehabilitation. Arteriovenous malformations can compromise the cerebral parenchyma by mass effect, by hemorrhage, and by "stealing" blood from adjacent tissue. Subarachnoid hemorrhage (SAH) can result in sympathetic stimulation, hydrocephalus, meningeal irritation, fluid and electrolyte disturbances, and cerebral vasospasm. Excision may result in massive cerebral hemorrhage and edema as arterial pressures are abruptly normalized. Anesthetic management is guided by a full evaluation of the patient's pathophysiology and medical management. The anesthetist must understand the total impact of the AVM, compensatory responses, and the hazard of surgery and anesthesia. The goal is to achieve a balance in oxygen supply and demand at a pressure sufficient to perfuse the brain tissue without exceeding the pressure limits of compromised vasculature. This must be done while providing optimal brain relaxation for excision with minimal bleeding.