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

Abstract

Histologic evidence of damage to the ductus arteriosus after the infusion of prostaglandin E 1 has 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 E 1 group) comprised 12 neonates who received prostaglandin E 1 and died while receiving it or within 4 days after its administration was discontinued; the mean duration of prostaglandin E 1 administration was 18 hours (range 30 minutes to 40 hours). Group 2 (control group) comprised 10 neonates who did not receive prostaglandin E 1 and 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 <0.0025). Histopathologic abnormalities reported by other investigators were found in only two patients from each group. Cineangiograms obtained at the repeat cardiac catheterization up to 33 months after prostaglandin E 1 treatment in 28 infants showed no abnormality at the ductus area; in all but 1 infant, the ductus either spontaneously closed or had been surgically ligated uneventfully. In an additional 33 patients, clinical follow-up did not suggest any problems in the ductus. It is concluded that the administration of prostaglandin E 1 may delay the normal closing process or maturation of the ductus but does not have any significant deleterious morphologic or clinical effect, and that the ductus arteriosus closes normally after prostaglandin E 1 is discontinued. Prolonged administration of prostaglandin E 1 )more than 40 hours) may cause the histologic changes observed by others.