Morphologic features of the ductus arteriosus after prostaglandin E1administration for ductus-dependent congenital heart defects

Histologic evidence of damage to the ductus arteriosus after the infusion of prostaglandin E1has been reported in neonates with ductus-dependent congenital heart defects. The reported changes suggested structural weakening of the ductus that might render it prone to laceration or rupture. The morphologic features of ductus arteriosi were studied in two groups of neonates with ductus-dependent congenital heart defects. Group 1 (prostaglandin E1group) comprised 12 neonates who received prostaglandin E1and died while receiving it or within 4 days after its administration was discontinued; the mean duration of prostaglandin E1administration was 18 hours (range 30 minutes to 40 hours). Group 2 (control group) comprised 10 neonates who did not receive prostaglandin E1and were matched with group 1 for weight, type of congenital heart defect and age at death.The length of the ductus and its internal diameter at the aortic end were greater in group 1 than in group 2, but the differences were not statistically significant. The internal diameter of the ductus at the pulmonary end was significantly greater in group 1 than in group 2 (p <0.05). Histologic staging of maturation of the ductus (stage 1 being most immature and stage 4 being most mature or functionally closed) showed that the ductus arteriosi of group 1 were significantly more immature than those of group 2. Maturational stage averaged 1.67 ± 0.30 (mean ± standard error of the mean) in group 1 and 3.00 ± 0.29 in group 2 (p