Effects of prostaglandin E1 given in low doses on the histopathology of the arterial duct.

The histopathology of the arterial duct was studied in relation to the maximal infusion rate of prostaglandin E1 administered in 35 infants with congenital heart disease. Two groups were distinguished based on the maximal infusion rate. The group receiving prostaglandin at low dose received 0.01 to 0.05 micrograms/kg/min (16 cases), the group having a high dose received greater than 0.05 to 0.7 micrograms/kg/min (19 cases). The histopathology was compared between the groups. Ductal damage was less common in the cases receiving a low rate of infusion than in those having a high rate of infusion. Multivariate analysis showed no relation between ductal pathology and the age of onset or duration of treatment, nor on the total dose of prostaglandin E1. Histological abnormalities were more common in patients with a gestational age equal to or greater than 40 weeks. Ductal damage was less common in patients with pulmonary atresia or stenosis compared with other anatomic diagnoses. Low dose infusions are recommended for treatment with prostaglandin E1 in infants with congenital heart disease.