Background Congenital lung malformations (CLM) are a heterogenous group of anomalies diagnosed with increasing frequency antenatally. Malignant transformation has been reported, causing debate on prophylactic excision in asymptomatic patients.

Objective To identify risk factors for adverse outcomes in infants that had surgery for symptomatic CLM

Methods Single centre retrospective observational study (January 1995-December 2023) of all children with CLM that underwent resectional surgery

Results Forty-nine infants (33 males) underwent surgery for CLM at 5 (1-10) days. Antenatal diagnosis was established in 45 (91.8%) patients and 18 underwent antenatal intervention (thoraco-amniotic shunt n=24, aspiration n=3, laser ablation n=3). Mediastinal shift was detected antenatally in 27 (55%), who were more likely to have had antenatal interventions (p=0.001) but did not exhibit worse outcomes. Survival was 91.8% (45/49). Early delivery (p=0.014), lower birthweight (p=0.015), pre-operative ventilatory requirement (p=0.04) and pre-operative pneumothorax (p=0.005), higher pre-operative oxygen requirement and oxygenation-index were associated with death. Six infants had malignant changes on histology. Those cases were more likely to require pre-operative intubation (p=0.008), have higher oxygen requirements pre-operatively (median 45%, range 30?80, p=0.013) and a longer duration of respiratory support post-operatively (median 11 days, range 5?18, p=0.035).

Conclusions We have identified factors associated with adverse outcomes including malignant changes arising from CLMs which may help inform surgical management.