Common Arterial Trunk: Physiology, Imaging, and Management

Common arterial trunk (CAT), or truncus arteriosus, is a rare form of cyanotic congenital heart disease and is highly associated with DiGeorge syndrome (microdeletion 22q11.2). Prenatal diagnosis is highly feasible, allowing proper delivery planning and postnatal management. The clinical presentation is highly variable depending on the anatomical variation; however, most commonly presenting with mild cyanosis and significant tachypnea, although these patients can often go undetected in the immediate newborn period. Transthoracic echocardiography is adequate for diagnosis and detailed anatomical delineation in the majority. Additional imaging modalities such as cardiac catheterization, computed tomography angiography, or cardiac magnetic resonance imaging can be helpful in those with more complex pulmonary artery (PA) or aortic anatomy, or in the older repaired. The surgical management of CAT is complete repair in the neonatal period with resection of branch PAs from the CAT with placement of a right ventricular (RV)-to-PA conduit and patch closure of the ventricular septal defect. Overall surgical outcomes are excellent in most centers, with the expectation that the child will eventually outgrow the RV-to-PA conduit and require reoperation. Other potential reoperations or postsurgical interventions in addition to the RV-to-PA conduit may involve the truncal valve or branch PAs.