Abstract
Human ductus arteiosus was studied histopathologically in 28 infants who had been diagnosed prolonged patency clinically, and in 70 infants without diagnosis of prolonged patency. The increased amount of elastic fiber in intimal cushion and subendotherial laminer elastosis was observed in almost all cases of persistent patent ductus arteriosus. These seemed more distinctive when the persistent period was elongate. On the other hand, in the seventy infants without prolonged patency, ductus showed slight increase of the elastic tissue in intimal cushion in proportion to gestational age and there was no distinctive subendotherial laminer elastosis. It is suggested that hemodynamic stress to the ductal wall play a singificant effect to increase the elastic fiber in the intimal cushion and development of the subendotherial laminer elastosis.
