LONG-TERM MRI CHANGES IN BRAIN AFTER PEDIATRIC OPEN-HEART-SURGERY

We performed magnetic resonance imaging (MRI) on the brain and neurolo gic examinations on 23 children after open heart surgery for congenita l heart disease. Twenty children also had psychometric assessments. Ex aminations were performed at a mean age of 66 months (range, 26 to 180 months). Age at operation was less than 1 month in 43% and more than 6 months in 45%. Abnormal scans were found in 17 (74%) and showed diff use findings consistent with hypoxic-ischemic encephalopathy, with or without areas of cortical infarction; focal cortical infarction alone; and (in one patient) callosal agenesis and abnormal neuronal migratio n. Normal IQ and neurologic examinations were found in all six of thos e who had a normal MRI, and five of six children with changes consiste nt with focal cortical infarction without diffuse change had a normal neurologic examination. Cerebral palsy and mental retardation was comm on in the group with diffuse abnormality (in eight of nine children), and this was more likely to occur in those who underwent prolonged (> 45 minutes) hypothermic circulatory arrest and operation during early infancy (P = .004). Focal cortical findings without diffuse changes we re more likely in those who underwent open heart surgery without hypot hermic circulatory arrest and were older than 6 months at operation, a nd these children were less likely to have frank neurodevelopmental se quelae. Thus, in our population, focal cortical lesions were common af ter open heart surgery, and, in addition, diffuse brain abnormality on MRI plus neurologic sequelae were common after prolonged hypothermic circulatory arrest.