Abstract Introduction Congenital lobar emphysema (CLE) is a rare developmental lung malformation characterized by overexpansion of a pulmonary lobe and compression of surrounding tissue normal tissue of the ipsilateral lung. Although 50% of cases present in the newborn period, diagnosis can be delayed when CLE coexists with congenital heart disease (CHD), as overlapping symptoms such as tachypnea and cyanosis are often attributed to cardiac dysfunction. Approximately 14-20% of patients with CLE have associated CHD, most commonly a ventricular septal defect (VSD). We report a case of an infant with Tetralogy of Fallot (TOF) and Absent Pulmonary Valve who developed unexpected postoperative respiratory distress and difficulty with ventilation, which uncovered a missed pulmonary malformation. Case Presentation A three-month-old girl with TOF and Absent Pulmonary Valve underwent corrective cardiac surgery. Preoperative chest radiograph showed right lung hyperaeration with mediastinal shift, but this finding was not initially recognized as CLE. Intraoperatively, the right lung appeared markedly emphysematous with leftward mediastinal deviation. Postoperatively, the infant developed persistent respiratory distress and difficulty in ventilation. Repeat chest imaging showed worsening left lung collapse, compensatory hyperinflation, and herniation of the right lung across the mediastinum. Despite intensive ventilatory support, she remained dependent on the ventilator. Persistent wheezing was managed with corticosteroids, magnesium sulfate, and nebulized bronchodilators. With gradual clinical improvement and resolution of infection, she was transitioned to non-invasive positive pressure ventilation, then to room air. She was discharged after 47 hospital days—43 days post-surgery and 19 days post-extubation. Discussion CLE is estimated to occur in 1 in 20,000-30,000 live births and is more common in males. It usually involves the left upper lobe but may affect any lobe. The condition results from partial bronchial obstruction due to intrinsic cartilage deficiency or external vascular compression, creating a “ball-valve” effect that traps air and causes lobar hyperinflation. In infants with CHD, CLE can remain silent until changes in pulmonary mechanics after surgery unmask the underlying defect. Conclusion CLE can present unexpectedly in the postoperative period. Although uncommon, it is an important differential diagnosis in infants presenting with respiratory distress particularly those with coexisting CHD. Preoperative imaging should be carefully reviewed to identify such pulmonary anomalies. Early recognition and appropriate multi-disciplinary team management are essential to prevent complex cardiopulmonary complications. This abstract is funded by: None
Agudo et al. (2026) studied this question.