64 INTERNAL CAROTID ARTERY BLOOD FLOW VELOCITIES BEFORE, DURING AND AFTER EXTRACORPOREAL MEMBRANAE OXYGENATION (ECMO)

Abstract

In 24 infants (mean birth weight 3.3 +/-.09 kg) requiring ECMO, blood flow velocities in the internal carotid arteries were studied using pulsed doppler ultrasound. Systolic, mean and diastolic flow velocities were calculated in cm/s. Four infants had right common carotid repair. Fifteen healthy term babies (mean birth weight 3.4 +/-.11 kg) were used as controls. During ECMO. mean and diastolic flow velocities in the left internal carotid artery increased significantly (p<.05) (mean flow velocity 70%, diastolic flow velocity 123%). After ECMO,- systolic and mean flow velocities in the left internal carotid artery remained significantly elevated when compaired to control (p<.05). During ECMO, 48% of the infants had forward flow in the right internal carotid artery. No differences were found between the blood flow velocities in the left and the forward blood flow velocities in the right internal carotid artery during ECMO. The blood flow velocities in the left and in the right internal carotid artery appear similar in the 4 patients with right common carotid repair. Our results suggest a nigh prevalence of large collaterals between right and left internal carotid artery. The increase in left diastolic flow velocity may be due to ECMO pump action or decreased resistance. Carotid repair appears effective in restoring normal blood flow velocities.