C65-13 Pulmonary Sequelae of Complex Congenital Heart Disease With Major Aortopulmonary Collateral Arteries

Abstract Introduction Congenital heart disease (CHD) highlights heart and lung interconnectivity, however the pulmonary implications of many severe CHDs are largely unknown. Tetralogy of Fallot in its most severe form is characterized by pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries (PA/VSD/MAPCAs). MAPCAs develop from other systemic arterial sources in utero to supply blood to the lungs. Each patient is unique in MAPCA number, arterial source, and relationship to lung segments. Management of PA/VSD/MAPCAs is challenging and the long-term, structural respiratory sequelae are not well documented. Here we present thoracic CT findings in a retrospective cohort of PA/VSD/MAPCAs patients. Methods PA/VSD/MAPCAs patients who received management and chest CT imaging at BC Children’s Hospital in Vancouver, Canada (2012-2023) were identified by key phrase searches in discharge information and echocardiogram reports. Charts were reviewed for relevant clinical details. CT images were reviewed by two radiologists for bronchiectasis, airway compression, parenchymal changes, MAPCA anatomy (origin and destination), and native pulmonary artery anatomy. CT images were quantitatively analyzed for lung, lobe and pulmonary vessel density and volume using VIDA Insights software. Results 40 pediatric patients (age 0-18 years; N = 22 female) were identified with PA/VSD/MAPCAs and received a chest CT during the study timeframe (Figure 1A). The median MAPCA number was 3(1,8). Native pulmonary arteries were absent in 35% and confluent in 63%. Bronchiectasis was present in 13 patients (22% right lung and 22% left lung; not always bilaterally) (Figure 1B). Parenchymal abnormalities were present on 8 pre-operative neonatal CTs (only 3 would develop bronchiectasis). Parenchymal and airway qualitative analysis and quantitative analyses are ongoing (Figure 1C-E) and will be reported co-localized to MAPCA lobar supply. Conclusions PA/VSD/MAPCAs relies on collateral arterial supply for pulmonary blood supply, yet the respiratory and airway sequelae of this condition is largely unknown. In our study, most patients had multiple MAPCAs with varying pulmonary artery anatomy. Here we present evidence of pulmonary sequelae on CT, specifically high prevalence of bronchiectasis, indicating chronic airway inflammation and/or infection. This has not previously been demonstrated in a similarly sized cohort. Bronchiectasis is not benign, requiring surveillance, physiotherapy, and pharmacologic management, and thus its radiographic recognition is important for patient management. Additional respiratory sequelae (lobar density, parenchymal changes, airway compression) and quantitative CT metrics will be discussed. In summary, structural lung changes, particularly bronchiectasis, are relatively common in children with PA/VSD/MAPCAs, providing clinical relevance and highlighting the need for further research. This abstract is funded by: UBC Clinical Investigator Program