Abstract 1922: Preoperative Brain Injury in Transposition of the Great Arteries is Predicted by Oxygenation and Time to Surgery, Not by Balloon Atrial Sepstostomy
Introduction: Brain injury in the form of periventricular leukomalacia (PVL), a watershed white matter injury, and arterial ischemic stroke (AIS) affect a high proportion of infants born with severe congenital heart defects after surgery. MRI studies have shown both PVL and AIS occur in preoperative infants as well. Recently, balloon atrial septostomy (BAS) was implicated in preoperative AIS in neonates with transposition of the great arteries (TGA).
Hypothesis: We hypothesized that the overall incidence of AIS is low in these neonates, and not associated with BAS.
Methods: Infants with TGA were enrolled as part of a larger prospective study to determine the prevalence of preoperative brain injury. Inclusion criteria were full-term gestation (40 ± 4 weeks), intention to undergo surgical repair, and medical stability for 24 hours prior to surgery. Clinical data on these patients was retrospectively reviewed, including performance of BAS and use of heparin. All preoperative arterial blood gases and pulse-oximetry recordings were cataloged. Brain MRI was completed on the day of surgery and reviewed by a neuroradiologist blinded to the patients’ clinical status. Scans were reviewed for the presence of hemorrhage, AIS, and PVL. Multivariate risk analysis and repeated measures ANOVA were performed.
Results: There were 26 neonates with TGA; 14 underwent BAS. Following BAS, the PaO2 improved from a mean of 27.9 to 38.7 torr (p<0.01). Heparin was not used in any of the procedures. Brain imaging identified AIS in none of the 26 neonates. PVL was seen in 10 neonates (6 with BAS) and was not associated with BAS (p=0.70). Taken together, increased time to surgery (p=0.026) and lower PaO2 (p=0.024) were highly predictive of PVL. Neonates with PVL had a lower daily mean PaO2 (p=0.020). Among the 14 neonates who underwent BAS, 6 had PVL, but those with a higher post-BAS mean PaO2 were less likely to have PVL (p=0.021).
Conclusions: The occurrence of PVL was not associated with BAS, and preoperative AIS was not seen in any of the neonates with TGA. PVL was frequently seen and was associated with lower PaO2 and increased time to surgery. Our data suggest that successful BAS resulting in increased PaO2 in cyanotic neonates with TGA is likely to decrease their risk of brain injury.