Lung ultrasound evolution after interventional closure of the ductus in preterm babies.

Interventional closure of patent ductus arteriosus (PDA) in preterm infants may result in significant hemodynamic and pulmonary changes. Lung ultrasound (LU) is increasingly used to assess pulmonary aeration; however, data on early respiratory changes following PDA closure remain limited. A prospective observational study was conducted including preterm infants born at ≤ 32 weeks' gestation with hemodynamically significant PDA undergoing surgical or catheter-based closure between May 2022 and November 2025. LU was performed the day before intervention and at 1-2 h, 6-12 h, 24 h, and 2-3 days after closure. Oxygenation (S/F ratio) and invasive mechanical ventilation (IMV) use were also evaluated. Seventeen infants were included (15 catheter-based, 2 surgical closures). A transient deterioration in oxygenation and increased odds of IMV were observed within the first hours after ductal closure. This was followed by a significant improvement in lung ultrasound score at 2-3 days. Conclusion: Lung aeration improved 2-3 days after interventional PDA closure in preterm infants. Lung ultrasound may be a useful bedside tool to monitor dynamic pulmonary changes during the early post-closure period.