Bose and Laughon have clearly reviewed the lack of evidence for current treatments of patent ductus arteriosus (PDA) in preterm infants.[1] As highlighted, the general tendency to treat a clinically relevant PDA for fear of adverse clinical outcome with either indomethacin or surgery when indomethacin fails has caused a lack of information on the natural history of symptomatic PDA. Spontaneous PDA closure has been reported beyond the first weeks of life.[2] Therefore, a more conservative approach towards PDA treatment may be rational, even at a later stage. We report successful closure of a symptomatic PDA several weeks postnatally in a preterm baby after fluid restriction and diuretics.

A preterm boy of 28 weeks and one day received prophylactic indomethacin 0.1 mg/kg/day once daily during the first three days of life. At day 1, a unilateral IVH grade 2 was noticed. Despite ventilation and surfactant, oxygenation problems persisted. A cardiac ultrasound at day 5 showed evidence of pulmonary hypertension and a functionally closed ductus arteriosus. Nitric oxide was administered for a week and the boy was weaned from the ventilator at three weeks of age. At one month of age a cardiac murmur was noticed while oxygen need and CPAP dependency persisted. Cardiac ultrasonography demonstrated ductus arteriosus patency with significant left-to-right shunting. Despite a long course of indomethacin (0.2 mg/kg/day during 6 days), ductal patency persisted as shown by cardiac ultrasound. Treatment with fluid restriction (130 ml/kg/day) and diuretics (furosemide 1 mg/kg/day for 3 days followed by triamterene and hydrochlorothiazide 2 mg/kg/day for 14 days) was initiated. Adequate growth was maintained. During treatment, both nasal CPAP and supplemental oxygen could be stopped. By ultrasound at the age of 7 weeks, the ductus arteriosus was shown to have closed.

This case underlines both the possibility of the ductus reopening after indomethacin prophylaxis and the low probability of indomethacin to induce ductal closure at several weeks postnatally. Recently, Vanhaesebrouck and colleagues have presented data to suggest that fluid restriction along with ventilatory adjustments is effective in closing a symptomatic PDA diagnosed within 72 hours postnatally in preterm infants.[3] Our case suggests potential efficacy of a similar conservative approach to PDA beyond the first days to weeks after birth. We wish to emphasize the possibility of a conservative approach as a treatment option and an alternative to surgery in clinically relevant PDA beyond the first weeks of life. Additional studies are needed to evaluate the efficacy of conservative treatment of PDA as compared to indomethacin and surgical closure, depending on the postnatal age.

1 Bose CL, Laughon MM. Patent ductus arteriosus: lack of evidence for common treatments. Arch Dis Child Fetal Neonatal Ed. 2007;92(6):F498-502.

2 Koch J, Hensley G, Roy L et al. Prevalence of spontaneous closure of the ductus arteriosus in neonates at a birth weight of 1000 grams or less. Pediatrics. 2006;117(4):1113-21.

3 Vanhaesebrouck S, Zonnenberg I, Vandervoort P et al. Conservative treatment for patent ductus arteriosus in the preterm. Arch Dis Child Fetal Neonatal Ed. 2007;92(4):F244-7.