Lobar emphysema associated with patient ductus arteriosus and pulmonary obstructive vascular disease.

Three cases of respiratory distress with patent ductus arteriosus are presented. The left-to-right shunt across the ductus arteriosus produced dilated pulmonary arteries and secondary bronchial compression, leading to lobar emphysema. The increase of blood flow across the ductus arteriosus causes structural changes of the wall of the preacinar and intra-acinar arteries. All three patients died, most probably from the association of parenchymatous pulmonary disease and pulmonary obstructive vascular disease.