Refractory Postoperative Chylothorax Following Adult Atrial Septal Defect Closure Managed with Multimodal Thoracoscopic Ligation and Chemical Pleurodesis: A Case Report

Abstract

Background: Postoperative chylothorax is uncommon after adult intracardiac surgery but may cause substantial nutritional, immunological, and respiratory consequences when drainage is persistent or high output. Case Description: A 34-year-old woman developed a large right-sided pleural effusion following elective pericardial-patch closure of a large ostium secundum atrial septal defect. Thoracentesis yielded milky fluid with a triglyceride concentration of 2,402 mg/dL, confirming chylothorax. Initial management comprised intercostal tube drainage, bowel rest, total parenteral nutrition, dietary modification, and subcutaneous octreotide. Despite more than 2 weeks of conservative treatment, chylous drainage remained high at 500–1,500 mL/day. The patient subsequently underwent right thoracoscopic-assisted supradiaphragmatic mass ligation of the thoracic duct and surrounding fibrofatty tissue. Drainage decreased, but a low-output chylous leak persisted following a high-fat dietary challenge. Salvage chemical pleurodesis was therefore performed using 500 mg of intrapleural doxycycline. Drain output subsequently decreased to less than 20 mL/day, the fluid became non-chylous, and radiographic lung expansion improved. The patient was discharged in a stable condition with the drain in situ. It was removed 10 days later after three consecutive days without drainage. No clinical or radiographic recurrence was observed during 3 months of follow-up. Conclusion: This case demonstrates the potential value of a staged multimodal approach comprising conservative therapy, thoracic duct ligation, and chemical pleurodesis for refractory postoperative chylothorax after adult atrial septal defect closure.