Outcomes following the surgical ligation of the patent ductus arteriosus in premature infants in Scotland.

OBJECTIVE: To determine morbidity, mortality and associated risk factors following patent ductus arteriosus (PDA) ligation in premature infants.

METHODS: Retrospective case note audit of premature infants referred to a national paediatric cardiothoracic surgical service (2001-2007) with univariate and multivariate analysis of potential risk factors for mortality and morbidity.

RESULTS: 125 infants were enrolled (median gestational age 26 weeks (IQR 25-27 weeks), median birth weight 840 g (IQR 730-1035 g)). Referral characteristics were median LA:Ao 1.8 (IQR 1.5-2.0), 80% ventilated, 18.4% continuous positive airway pressure, 70% diuretics and 58% prior treatment with cyclooxygenase inhibitors (COIs). Median age at PDA ligation was 31 days (IQR 25-41 days). Postoperative characteristics were median time to extubation 5 days (IQR 3-10 days), 36.0% corticosteroids, 46.8% domiciliary oxygen and 4.8% vocal cord palsy. The 30-day and 1-year mortality rates were 4.8% and 12.8%, respectively, with neurodisability in 32% of survivors. All deaths occurred in the ventilated group and were mainly attributable to bronchopulmonary dysplasia (BPD). Gestation and fractional inspired oxygen (FiO(2))>60% were significantly associated with 30-day mortality. FiO(2), ventilation, lack of prior COIs and postoperative corticosteroids were significantly associated with 1-year mortality. Preoperative FiO(2)>40% and lack of prior COIs retained independent significance for death at 1 year.

CONCLUSIONS: PDA ligation is well tolerated, with evidence of early benefit. The incidence of neurodisability or death from BPD at 1 year remains high. Increasing preoperative FiO(2) and lack of prior treatment with COIs are associated with increased mortality at 1 year.