Abstract 19890: Pre-operative Cerebral Hemodynamics From Birth Until Surgery in Neonates With Critical Congenital Heart Disease

Introduction: Neonates with critical congenital heart disease (CHD) exhibit a high prevalence of white matter injury (WMI). Recent work in neonates with hypoplastic left heart syndrome has shown that a longer wait from birth to surgery was associated with lower cerebral tissue oxygen saturations (StO2) on the morning of surgery and an increased risk for postoperative white matter injury (WMI). Understanding the daily preoperative changes in cerebral physiology during this vulnerable period may lead to new therapeutic algorithms aimed at prevention of WMI. Methods: Term neonates with critical CHD were recruited for this study. Frequency domain diffuse optical spectroscopy was employed to noninvasively quantify StO2. Daily StO2 measurements were made from day of recruitment until the day of surgery. Results: We studied 37 neonates with critical CHD. Operations were performed at 1-8 days of life. Non-elective reasons for timing of surgery resulted only in earlier surgery in this cohort. The subjects were placed in 2 groups depending on if they had a normal arch (N=20) or obstructed arch (N=17). In a linear mixed-effects model, StO2 decreased as a function of time from birth but was not specific to diagnostic group. Conclusions: Observed longitudinal daily decline in StO2 from birth until surgery supports our earlier findings and extends them to other groups of CHD. These results suggest that reported increases in risk for WMI with time-to-surgery could be due to mismatched oxygen delivery to metabolic demand. Therapeutic interventions such as increasing cerebral blood flow or decreasing cerebral oxygen demand may be considered when earlier surgery is not possible.