Right common carotid artery ligation for extracorporeal membrane oxygenation: cerebral blood flow velocity measurement with Doppler duplex US.

Duplex Doppler ultrasound (US) provides a noninvasive method of monitoring cerebral blood flow velocity in newborns. The authors observed the changes in cerebral blood flow velocity in the right middle cerebral artery (RMCA) in 15 neonates during right common carotid artery (RCCA) ligation for extracorporeal membrane oxygenation. Antegrade flow in the RMCA continued uninterrupted in all patients at the moment of ligation. Peak systolic velocity decreased initially and then increased to 70% of baseline levels in the following 3-5 minutes. End diastolic velocity remained relatively unchanged at the time of ligation and rose slightly above baseline during the following 3-5 minutes. This study demonstrates that at the time of RCCA ligation, collateral flow is immediately established in the RMCA distribution and is further augmented within minutes.