Transcranial Doppler-revealed retrograde cerebral artery flow during Norwood 1 operation.

We describe a 6-week-old girl with a hypoplastic left heart syndrome in whom multimodal neuromonitoring was used during Norwood stage I palliation. After placement of modified Blalock-Taussig shunt, transcranial Doppler measurements revealed retrograde flow in the right middle cerebral artery throughout the cardiac cycle. Further examination showed that the change in cerebral blood flow was secondary to shunt runoff and clinical correlation was noted in near infrared spectroscopy measurements of regional cerebral oxygenation saturation.