Management of the persistent ductus arteriosus in infants of very low birth weight: early and long-term results*1

PDA ligation and health outcomes: a meta-analysis

BACKGROUND AND OBJECTIVE

Patent ductus arteriosus (PDA) ligation has been variably associated with neonatal morbidities and neurodevelopmental impairment (NDI). The objective was to systematically review and meta-analyze the impact of PDA ligation in preterm infants at <32 weeks' gestation on the risk of mortality, severe neonatal morbidities, and NDI in early childhood.

METHODS

Medline, Embase, Cochrane Central Register of Controlled Trials, Education Resources Information Centre (ERIC), Cumulative Index to Nursing and Allied Health (CINAHL), PsycINFO, and the Dissertation database were searched (1947 through August 2013). Risk of bias was assessed by using the Newcastle-Ottawa Scale and the Cochrane Risk of Bias tool. Meta-analyses were performed by using a random-effects model. Unadjusted and adjusted odds ratios (aORs) with 95% confidence intervals (CIs) were pooled when appropriate.

RESULTS

Thirty-nine cohort studies and 1 randomized controlled trial were included. Nearly all cohort studies had at least moderate risk of bias mainly due to failure to adjust for survival bias and important postnatal preligation confounders such as ventilator dependence, intraventricular hemorrhage, and sepsis. Compared with medical treatment, surgical ligation was associated with increases in NDI (aOR: 1.54; 95% CI: 1.01-2.33), chronic lung disease (aOR: 2.51; 95% CI: 1.98-3.18), and severe retinopathy of prematurity (aOR: 2.23; 95% CI: 1.62-3.08) but with a reduction in mortality (aOR: 0.54; 95% CI: 0.38-0.77). There was no difference in the composite outcome of death or NDI in early childhood (aOR: 0.95; 95% CI: 0.58-1.57).

CONCLUSIONS

Surgical ligation of PDA is associated with reduced mortality, but surviving infants are at increased risk of NDI. However, there is a lack of studies addressing survival bias and confounding by indication.

Risk factors for isolated periventricular leukomalacia

Periventricular leukomalacia, a major cause of neurologic disabilities in preterm infants, can be isolated or associated with intraventricular and periventricular hemorrhage. To determine the risk factors for isolated periventricular leukomalacia, we retrospectively studied the characteristics of all very low birth weight infants affected by isolated periventricular leukomalacia who were delivered over a 5-year period and compared them with a control group of very low birth weight infants, matched within 2 weeks for gestational age, with no central nervous system pathology, and born during the same period. In total, 20 affected infants were compared with 98 control infants. Neonatal sepsis caused by coagulase-negative Staphylococcus (P = 0.014) and neonatal seizure (P = 0.026) were associated with isolated periventricular leukomalacia only on univariate analysis. Three variables demonstrated statistically significant associations with isolated periventricular leukomalacia on both univariate and multivariate logistic regression analysis as independent risk factors: birth weight (odds ratio, 4.31; 95% confidence interval, 1.54-12.06; P = 0.005), early neonatal hypotension requiring combined inotropic therapy (odds ratio, 4.90; 95% confidence interval; 1.22-19.68, P = 0.025), and delayed surgical closure of hemodynamically significant patent ductus arteriosus beyond age 7 days (odds ratio, 1.20; 95% confidence interval, 1.06-1.35; P = 0.003).