Clarifying the Pulmonary Arterial Morphology and Pulmonary Blood Supply in Patients with Tetralogy of Fallot and Pulmonary Atresia on Computed Tomography Angiography

Aim. The present study sought to characterize the pulmonary arterial morphology and pulmonary blood supply in patients of tetralogy of Fallot and pulmonary atresia (TOF-PA) on CT angiography. Materials and Methods. We retrospectively reviewed our departmental database to identify patients with TOF-PA evaluated using CT angiography. The images were analysed to detect the presence of main and branch pulmonary arteries and pulmonary arterial confluence, presence of major aortopulmonary collateral arteries (MAPCAs), laterality and relation with pulmonary arterial morphology, and presence of patent arterial duct and associated intra- and extracardiac anomalies. Results. TOF-PA was identified in 177 patients (114 (64.4%) males; median age: 9 months). Pulmonary arteries were confluent in 142/177 (80.2%) patients. According to Somerville classification, type II pulmonary atresia was the most frequent pattern seen in 127/177 (71.8%). Based on McGoon's ratio, pulmonary arteries were adequate for surgery in 123/177 (69.5%) patients. Patent arterial duct was present in 84/177 (47.5%) patients while MAPCAs were present in 124 (70.1%) patients, of which 72/124 (58.1%) patients had at least 1 essential MAPCA supplying either lung. According to Congenital Heart Surgeons' Society classification, type B pulmonary arterial anatomy was the most prevalent, seen in 103/177 (57.6%) patients. Conclusion. TOF-PA is associated with marked morphologic variability in the pulmonary arterial arborization to supply the lungs. Cardiac CT angiography can accurately delineate the pulmonary arterial morphology, sources of pulmonary blood supply, and associated cardiovascular anomalies in patients with TOF-PA which aids in planning appropriate surgical management including decisions regarding the need for unifocalization of MAPCAs.