Neurologic and psycho-intellectual outcome related to structural brain imaging in adolescents and young adults after neonatal arterial switch operation for transposition of the great arteries

ObjectiveWe studied brain structure abnormalities in adolescents and young adults who had undergone the neonatal arterial switch operation for transposition of the great arteries and related them to the neurologic and psycho-intellectual outcomes.MethodsIn a prospective longitudinal study, 60 unselected adolescents and young adults who had undergone surgery with combined deep hypothermic circulatory arrest and low flow cardiopulmonary bypass were re-evaluated at a mean age of 16.9 ± 1.7 years to determine their clinical neurologic status, intellectual development, and psychological condition. The results were related to population norms and anatomic structural abnormalities assessed by brain magnetic resonance imaging, with consideration of the risk factors in the preoperative and perioperative periods.ResultsNeurologic impairment was more frequent (10%) than in the normal population. Although the average full-scale, verbal, and performance intelligence quotients were not reduced, scores >2 standard deviations less than the expected mean were increased. Above average scores were found for analytical thinking, but the orthography testing results were reduced. The self-rated psychological condition was better than expected. Magnetic resonance imaging demonstrated moderate or severe structural brain abnormalities in 32% of the patients. Periventricular leukomalacia was detected in >50%; its severity correlated with the grade of neurologic impairment, which correlated significantly with reduced intelligence, analytical thinking, and orthography. Preoperative acidosis and hypoxia were the only independent patient-related risk factors for neurologic dysfunction, reduced intelligence, periventricular leukomalacia, and reduced brain volume.ConclusionsDespite encouraging overall neurodevelopmental outcomes, a significant minority had performances below the expected level, emphasizing the need for ongoing surveillance. Considering the high frequency of structural brain abnormalities, prospective long-term studies are needed to define their prognostic value with respect to the neuropsychological outcomes in childhood and adolescence.