Objectives: To determine the impact of surgical and therapeutic risk factors on pre- and postoperative brain MRI findings in neonates with complex congenital heart disease.
Methods: We performed a retrospective analysis of neonates with hypoplastic left heart syndrome (HLHS) and d-transposition of the great arteries (d-TGA) who underwent a pre- and postoperative brain MRI studies between 2009 and 2017 in one center. MR images were graded according to a scoring system devised by Andropoulos et al. Patients born < 36 weeks’ gestation, those with genetic abnormalities or dysmorphic features were excluded. Groups were compared in terms of pre- and postoperative brain injury scores, as well as perioperative risk factors.
Results: Twenty neonates with HLHS who underwent a Norwood procedure and 28 neonates with d-TGA who underwent an arterial switch operation were identified and met our criteria. Patients undergoing a Norwood procedure had a significantly longer deep hypothermic circulatory arrest time (47 vs. 10 minutes; p < 0.001), longer time of ventilation (p = 0.004), longer stay on CICU (p < 0.001), and longer hospital stay (p < 0.001) compared with patients undergoing an arterial switch operation. Preoperative brain MRI was abnormal in 27 of 48 neonates (56%) with no significant differences between the two groups regarding total injury score (p = 0.47). Postoperative MRI findings were abnormal in a total of 36 patients (75%) with no differences between HLHS and d-TGA (p = 0.44). Both groups showed a significant upward change in median total brain injury score from the preoperative to postoperative study (HLHS: p = 0.02; d-TGA: p = 0.04).
Conclusion: The total brain injury score was higher postoperatively in both HLHS and d-TGA compared with preoperative baseline values. The injury scores were not significantly different between these groups, either preoperatively or postoperatively. Longer deep hypothermic circulatory arrest time and longer duration of ventilation did not lead to a higher postoperative injury score in HLHS patients in comparison to the d-TGA group. Further studies are warranted to determine the prognostic value of these findings with respect to risk stratification of longitudinal neurodevelopmental outcomes.
