Relationship of Intraoperative Cerebral Oxygen Saturation to Neurodevelopmental Outcome and Brain Magnetic Resonance Imaging at 1 Year of Age in Infants Undergoing Biventricular Repair

Background-Near-infrared spectroscopy monitoring of cerebral oxygen saturation (rSO(2)) has become routine in many centers, but no studies have reported the relationship of intraoperative near-infrared spectroscopy to long-term neurodevelopmental outcomes after cardiac surgery. Methods and Results-Of 104 infants undergoing biventricular repair without aortic arch reconstruction, 89 (86%) returned for neurodevelopmental testing at 1 year of age. The primary near-infrared spectroscopy variable was the integrated rSO(2) (area under the curve) for rSO(2) <= 45%; secondary variables were the average and minimum rSO(2) by perfusion phase and at specific time points. Psychomotor and mental development indexes of the Bayley scales, head circumference, neurological examination, and abnormalities on brain magnetic resonance imaging did not differ between subjects according to a threshold level for rSO(2) of 45%. Lower Psychomotor Development Index scores were modestly associated with lower average (r=0.23, P=0.03) and minimum (r=0.22, P=0.04) rSO(2) during the 60-minute period after cardiopulmonary bypass but not with other perfusion phases. Hemosiderin foci on brain magnetic resonance imaging were associated with lower average rSO(2) from postinduction to 60 minutes post cardiopulmonary bypass (71 +/- 10% versus 78 +/- 6%, P=0.01) and with lower average rSO(2) during the rewarming phase (72 +/- 12% versus 83 +/- 9%, P=.003) and during the 60-minute period following cardiopulmonary bypass (65 +/- 11% versus 75 +/- 10%, P=0.009). In regression analyses that adjusted for age <= 30 days, Psychomotor Development Index score (P=0.02) and brain hemosiderin (P=0.04) remained significantly associated with rSO(2) during the 60-minute period following cardiopulmonary bypass. Conclusions-Perioperative periods of diminished cerebral oxygen delivery, as indicated by rSO(2), are associated with 1-year Psychomotor Development Index and brain magnetic resonance imaging abnormalities among infants undergoing reparative heart surgery.