Chylothorax after pediatric cardiac surgery: pathophysiology, diagnosis, and evolving management strategies

Chylothorax is a significant complication following congenital heart surgery in children, with a reported incidence of 4 to 9%. It is associated with prolonged intensive care unit stay, nutritional depletion, immunodeficiency, coagulopathy, and a twofold increase in adjusted in-hospital mortality. Despite its importance, standardized management guidelines remain absent, and institutional practices vary widely. Risk factors include neonatal age, low body weight, genetic syndromes such as Noonan and Turner syndromes, higher surgical complexity, prolonged cardiopulmonary bypass time, cavopulmonary anastomosis procedures, and postoperative central venous thrombosis. Diagnosis relies on pleural fluid analysis demonstrating elevated triglycerides and lymphocyte predominance, although atypical presentations in fasting patients warrant heightened suspicion. Conservative management with medium-chain triglyceride diet or total parenteral nutrition resolves the majority of cases. Octreotide has been adopted widely as adjunctive pharmacotherapy, though high-quality evidence supporting its efficacy remains limited. For refractory cases, the management has evolved considerably with the advent of dynamic contrast-enhanced magnetic resonance lymphangiography, which enables classification of chylothorax and guides targeted catheter-based interventions such as thoracic duct embolization. This review synthesizes the current evidence on pathophysiology, risk stratification, diagnosis, and the stepwise management of postoperative chylothorax in children, with emphasis on emerging lymphatic imaging and interventional techniques.