Background Regional cerebral perfusion provides cerebral circulatory support during aortic arch reconstruction. We report the effectiveness of high-flow regional cerebral perfusion (HFRCP) from the right innominate artery to maintain sufficient cerebral and somatic oxygen delivery through collateral vessels. Methods Frontal cerebral and thoracolumbar probes to measure somatic regional oxygen saturation (rS o2 ) were used to continuously measure oxygenation during cardiopulmonary bypass in 18 patients (weight, 2.1 to 4.3 kg) who underwent arch reconstruction using HFRCP (mean flow, 82; range, 43 to 108 ml/kg/min). Procedures included 9 Norwood procedures, 5 coarctation of aorta/interruption of aorta complex repairs, and 4 aortic arch repairs for a single ventricle. Mean HFRCP duration was 51 ± 17 minutes under moderate hypothermia. Mean radial arterial pressure was kept at less than 50 mm Hg during HFRCP, and chlorpromazine (mean dose, 2.8 mg/kg) was given to all patients before and during HFRCP to increase regional cerebral perfusion flow. Plasma lactate concentration was measured before and after HFRCP. Results During HFRCP, mean cerebral rS o2 was 78.8% ± 9.5%, somatic rS o2 was 65.4% ± 12.1%, and lactate concentration increased from 3.8 ± 2.2 to 5.5 ± 2.1 mmol/L. There was significant correlation between regional cerebral perfusion flow and somatic rS o2 . Significant inverse correlations were noted between regional cerebral perfusion flow and the increase of lactate concentration and between somatic rS o2 and the increase of lactate concentration. Conclusions High-flow regional cerebral perfusion preserved sufficient cerebral and somatic tissue oxygenation during aortic arch repair. The reduction of vascular resistance of collateral vessels increased both cerebral and somatic blood flow, resulting in improved tissue oxygen delivery.