TRANSCRANIAL DOPPLER CHANGES DURING STAGED SURGICAL RESECTION OF CEREBRAL ARTERIOVENOUS-MALFORMATIONS - A REPORT OF 3 CASES

The removal of large arteriovenous malformations (AVMs) in stages has been advocated to reduce the risk of perioperative hyperemic complications. In three patients who had a two-stage surgical removal of their large (>6 cm) frontal AVMs, transcranial Doppler (TCD) was performed 1 day before and 1 day after each surgery. Arteries still feeding the AVM after the first procedure had an increase in mean velocity (MV) and a decrease in the pulsatility index (PI) in the period between the two surgeries. MV reactivity to carbon dioxide before each stage was higher in feeding arteries at the second surgery, suggesting that the total magnitude of the shunt through the AVM was lower in spite of flow recruitment. TCD can be used to monitor the hemodynamic changes after embolization or partial surgery and may be of help in better defining the optimal time for final resection.