Anaesthetic management of arteriovenous malformations of the vein of Galen.

Arteriovenous malformations of the vein of Galen, though rare, are associated with a significant mortality. The anaesthetic management of patients with this defect during surgery may be complicated by massive blood loss and congestive heart failure. Four patients under 18 months of age underwent craniotomies for arteriovenous malformations of the vein of Galen. Since two required a second craniotomy for ligation of residual feeding vessels, there were six procedures in the four patients. Average blood loss per procedure was estimated at 126 per cent of blood volume. One patient died during operation and one had an intra-operative cardiac arrest. Both of these patients had associated cardiac failure. In the presence of a compromised myocardium, sudden blood loss or attempts at induced hypotension may result in inadequate diastolic perfusion of the heart and precipitate cardiac arrest. Consequently, these patients should be maintained in a euvolaemic state with transfusion and attempts at controlled hypotension should be avoided.