DEVELOPMENTAL AND NEUROLOGIC STATUS OF CHILDREN AFTER HEART-SURGERY WITH HYPOTHERMIC CIRCULATORY ARREST OR LOW-FLOW CARDIOPULMONARY BYPASS

Background. Deep hypothermia with either total circulatory arrest or l ow-flow cardiopulmonary bypass is used to support vital organs during heart surgery in infants. We compared the developmental and neurologic sequelae of these two strategies one year after surgery. Methods. Inf ants with D-transposition of the great arteries who underwent an arter ial-switch operation were randomly assigned to a method of support con sisting predominantly of circulatory arrest or a method consisting pre dominantly of low-flow bypass. Developmental and neurologic evaluation s and magnetic resonance imaging (MRI) were performed at one year of a ge. Results. Of the 171 patients enrolled in the study, 155 were evalu ated. After adjustment for the presence or absence of a ventricular se ptal defect, the infants assigned to circulatory arrest, as compared w ith those assigned to low-flow bypass, had a lower mean score on the P sychomotor Development Index of the Bayley Scales of Infant Developmen t (a 6.5-point deficit, P=0.01) and a higher proportion had scores les s than or equal to 80 (i.e., 2 SD or more below the population mean) ( 27 percent vs. 12 percent, P=0.02). The score on the Psychomotor Devel opment Index was inversely related to the duration of circulatory arre st (P=0.02). The risk of neurologic abnormalities increased with the d uration of circulatory arrest (P=0.04). The method of support was not associated with the prevalence of abnormalities on MRI scans of the br ain, scores on the Mental Development Index of the Bayley Scale, or sc ores on a test of visual-recognition memory. Perioperative electroence phalographic seizure activity was associated with lower scores on the Psychomotor Development Index (P=0.002) and an increased likelihood of abnormalities on MRI scans of the brain (P<0.001). Conclusions. Heart surgery performed with circulatory arrest as the predominant support strategy is associated with a higher risk of delayed motor development and neurologic abnormalities at the age of one year than is surgery w ith low-flow bypass as the predominant support strategy.