Cerebral lesions on magnetic resonance imaging correlate with preoperative neurological status in neonates undergoing cardiopulmonary bypass surgery

Objectives: To determine the prevalence, spectrum and course of cerebral lesions in neonates with congenital heart disease (CHD) undergoing full flow cardiopulmonary bypass (CPB) surgery using magnetic resonance imaging (MRI) and to examine the correlation between cerebral lesions and clinical neurological abnormalities.

Methods: Prospective cohort study of neonates with d-transposition of the great arteries (n = 22), univentricular heart malformation with hypoplastic aortic arch (n = 6) and aortic arch obstructions (n = 2) undergoing CPB. Neonates underwent cerebral MRI and blinded standardized neurological examination before (median day 6) and after surgery (day 13). The MRI findings were compared with those of 20 healthy controls.

Results: Preoperative cerebral lesions were present in 7 of 30 patients (23%) with isolated mild or moderate white matter injury (WMI) (n = 4), isolated small cerebral stroke (n = 1) and combined WMI and stroke (n = 2). None of the healthy controls had cerebral lesions on MRI. CHD neonates with preoperative cerebral lesions had more neurological abnormalities (P = 0.01) than neonates without cerebral lesions. Low arterial oxygen saturation (P = 0.03) was a risk factor for preoperative cerebral lesions, while balloon atrioseptostomy (P = 0.19) was not. After surgery, preoperative cerebral lesions persisted in 5 of 7 neonates, and 2 neonates (7%) showed signs of additional WMI in their postoperative MRI.

Conclusions: In neonates with severe CHD, WMI was the predominant preoperative finding, while cerebral strokes were less frequent. New postoperative lesions were rare. Preoperative neurological abnormalities correlated with the presence of cerebral lesions on MRI.