Anterior Origin of the Main Pulmonary Artery From the Arterial Valvar Sinus Unusual Truncus Arteriosus

We describe the case of a newborn with 22q11− deletion and an unusual form of common arterial trunk with the main pulmonary artery arising anteriorly at the level of the common arterial valve sinus. Case reports: We report the case of a term newborn male who presented to our institution with a prenatal diagnosis of congenital heart disease. His mother was a 29-year-old woman with 22q11− deletion who was evaluated in the high-risk perinatal clinic after an abnormal fetal ultrasound. The initial fetal echocardiogram performed at 26 weeks of gestation showed a common arterial valve overriding a large subarterial ventricular septal defect, with no significant stenosis or regurgitation of this valve. The pulmonary arteries were not clearly identified. Subsequent fetal evaluation showed what appeared to be a main pulmonary artery arising anteriorly to the ascending aorta, very proximal to the common arterial valve, at the level of the arterial valvar sinus (Figure 1; Movie I). No infundibulum or separate right ventricular outflow tract or second semilunar valve could be visualized. Prenatal counseling was given toward the likely diagnosis of a truncus arteriosus. Figure 1. Fetal echocardiographic image obtained in an approximation of the long-axis plane with a single great artery arising over the crest of the ventricular septum. A large ventricular septal defect is visualized below the great artery. An additional vessel is seen coursing anterior to the great artery. LA indicates left atrium; LV, left ventricle; MPA, main pulmonary artery; and Aorta, ascending aorta beyond the origin of the pulmonary artery. After an uneventful term delivery with an Apgar score of …