Clinical aspects of very-low-birthweight infants showing reopening of ductus arteriosus

Background: Indomethacin is used to treat the hemodynamically significant patent ductus arteriosus in premature infants. Some infants show ductus arteriosus reopening after effective constriction by the drug. The purpose of this study was to examine the clinical characteristics of such infants. Methods: We studied 57 very-low-birthweight infants with effective constriction of patent ductus arteriosus by the initial course of indomethacin. They were classified into the reopened group if they developed hemodynamically significant patent ductus arteriosus again or into the closed group if they showed complete closure. Clinical characteristics were compared between the two groups. Results: Ductus arteriosus reopening was shown in 15 (26%) of the 57 infants. These 15 infants had successful clinical ductal closure after a subsequent course of indomethacin or oral mefenamic acid treatment or surgical ligation without any severe complications. Infants in the reopened group showed significantly higher rates of developing chronic lung disease at 36 weeks of gestation than those in the closed group (53% vs 18%; P = 0.009). Furthermore, multivariate logistic regression analysis revealed ductus arteriosus reopening was the only independent risk factor for developing chronic lung disease at 36 postconceptional weeks in this population (adjusted odds ratio, 6.1; 95% confidence interval, 1.4-31.2; P = 0.02). Conclusions: Incomplete closure of the ductus arteriosus is associated with recurrence of a clinically significant patent ductus arteriosus and reopening of the ductus after initial closure with indomethacin is associated with chronic lung disease.