Abstract 3278: Neuroanatomical Development of Infants Undergoing Heart Surgery Evaluated by QuantitativeThree-Dimensional Magnetic Resonance Imaging
Background - Increased survival in infants with congenital heart disease (CHD) has raised interest in the neurodevelopmental sequelae, but there is no data regarding neuroanatomical development in infants with critical CHD. Volumetric study of the brain using three- dimensional magnetic resonance imaging (3D-MRI) in infants with CHD can help to identify effects on anatomical development of the brain that may be associated with functional impairment.
Methods and Results - Thirty-nine infants with CHD were studied prospectively with brain 3D-MRI several months after heart surgery, and compared to nineteen healthy control infants. Neurodevelopmental assessment was performed using the Bayley Scales of Infant Development II. The global volume of gray matter (GM) was significantly reduced in the patients with CHD compared to normal control (P<0.001), while no significant difference of the volume of white matter (WM) was observed. Further, decrease of GM volume was more apparent in frontal lobe than that in temporal lobe. Multivariate analysis revealed that preoperative hypoxia is strongly associated with decreased frontal GM volume (P=0.007). HLHS and body weight are another factors associated with decreased frontal GM volume (P=0.047, and P=0.038, respectively). Other variables were not correlated with decreased GM volume in this cohort. Further, hypoxic patients have a trend toward smaller regional brain volumes, most prominently in frontal GM (P=0.017), as well as more delayed psychomotor development (P=0.05) than non-hypoxic patients. Of note, frontal GM volume was positively associated with the psychomotor developmental index (PDI) score (P=0.005), but not with mental developmental index score.
Conclusions - Brain developmental impairments occur in a number of infants with CHD, especially in those with hypoxia. This is the first report of quantitative volumetric analysis of the brain in infants with CHD, showing reduced GM volume in these infants, and may provide insight into the anatomical substrate for the developmental delay in infants with CHD. Longitudinal follow-up study in a larger population is needed to elucidate the significance of chronic hypoxia on impaired neuroanatomical development.