Impairment in brain maturation on magnetic resonance imaging is common in infants undergoing surgery for congenital heart disease

  • Dr Julia Gunn, Murdoch Childrens Research Institute, Melbourne, Australia
  • Dr Rod Hunt, The Royal Children's Hopsital, Australia
  • Dr Lee Coleman, The Royal Children's Hopsital, Australia
  • Dr John Beca, Starship Children's Hospital, Auckland, New Zealand
  • Dr Terrie Inder, Washington University, St Louis, United States
  • Dr Lara Shekerdemian, The Royal Children's Hopsital, Melbourne, Australia

    • Objective: To identify brain injury and maturation impairment in young infants undergoing cardiac surgery.
    Methods: 74 full-term infants undergoing surgery for CHD were enrolled in a prospective study of brain injury. Brain MRI was undertaken prior to surgery (MRI 1), 1 week following surgery (MRI 2) and at 2 months (MRI 3). T1, T2 and DWI were obtained with 1mm slices in axial and coronal planes. Two blinded assessors scored images for white matter injury (WMI), grey matter injury (GMI), maturation (cortical folding and myelination) and CSF spaces. Chi2 analysis was used to compare groups.
    Results: Median age at surgery was 7 days (IQR 3-15). Surgical procedures were: Norwood-type palliation (24), systemic-pulmonary artery shunts (13), arterial switch operations (20), common arterial trunk repairs (5), aortic arch repairs (10) and PA banding (2). Cardiopulmonary bypass was required in 63 (85%) patients. The age at MRI scan, and associated abnormalities are given in the Table. Maturation impairment was present in 70 (38%) of MRI scans. This was unrelated to gestational age, but was associated with early WMI, and subsequent increased CSF spaces (p<0.05). It was more common in cardiac anomalies requiring either a shunt procedure or truncus repair (p=0.007). Punctate white matter lesions were common on MRI 2. These were not related to either surgical procedure or the use of bypass.
    Conclusions
    WMI is common in young infants undergoing cardiac surgery. Impairment of maturation is also common, and is related to cardiac anomaly. This may predict subsequent brain injury and development.

    MRI abnormality MRI 1 (69) MRI 2 (59) MRI 3 (54) Total patients (74)
    Median age of scan (IQR) 4 (3-15) days 18 (14-25) days 61 (42-74) days
    WMI 9 (13%) 25 (42%) 9 (17%) 41 (55%)
    GMI 5 (7%) 3 (5%) 5 (9%) 7 (9%)
    CSF space 3 (4%) 20 (34%) 22 (41%) 31 (42%)
    Maturation delay 31 (45%) 29 (49%) 10 (13%) 40 (54%)