Lobar emphysema due to ductus arteriosus compressing right upper bronchus in an infant with congenital heart disease.

A 1-month-old boy with tetralogy of Fallot, pulmonary atresia, right aortic arch, and right ductus arteriosus, exhibited progressive right upper lobar emphysema since his birth. The emphysema was caused by the right ductus arteriosus compressing the right upper bronchus. After division of the ductus arteriosus the emphysema completely regressed. We should explore the cause of lobar emphysema thoroughly before lobectomy especially when it is extrinsic. The emphysema may regress by eliminating the extrinsic factor.