Catheter, MRI and CT Imaging in Newborns with Pulmonary Atresia with Ventricular Septal Defect and Aortopulmonary Collaterals: Quantifying the Risks of Radiation Dose and Anaesthetic Time.

A comprehensive understanding of the native pulmonary blood supply is crucial in newborns with pulmonary atresia with ventricular septal defect and aortopulmonary collaterals (PA/VSD/MAPCA). We sought to describe the accuracy in terms of identifying native pulmonary arteries, radiation dose and anaesthetic time associated with multi-modality imaging in these patients, prior to their first therapeutic intervention. Furthermore, we wanted to evaluate the cumulative radiations dose and anaesthetic time over the study period. Patients with PA/VSD/MAPCA diagnosed at < 100 days between 2004 and 2014 were identified. Cumulative radiation dose and anaesthetic times were calculated, with imaging results compared with intraoperative findings. We then calculated the cumulative risks to date for all surviving children. Of 19 eligible patients, 2 had echocardiography only prior to first intervention. The remaining 17 patients underwent 13 MRIs, 4 CT scans and 13 cardiac catheterization procedures. The mean radiation dose was 169 mGy cm2 (47-461 mGy cm2 ), and mean anaesthetic time was 111 min (33-185 min). 3 children had MRI only with no radiation exposure, and one child had CT only with no anaesthetic. Early cross-sectional imaging allowed for delayed catheterisation, but without significantly reducing radiation burden or anaesthetic time. The maximum cumulative radiation dose was 8022 mGy cm2 in a 6-year-old patient and 1263 min of anaesthetic at 5 years. There is the potential to generate very high radiation doses and anaesthetic times from diagnostic imaging alone in these patients. As survival continues to improve in many congenital heart defects, the important risks of serial diagnostic imaging must be considered when planning long-term management.