Persistent chylothorax despite complete thoracic duct ligation: lymphangiographic findings and outcomes of thoracic duct embolization.

OBJECTIVE: To evaluate the lymphangiographic findings and clinical outcomes of thoracic duct embolization (TDE) in patients with persistent chyle leaks following complete thoracic duct ligation (TDL) for postsurgical chylothorax, and to identify factors associated with the treatment success MATERIALS AND METHODS: A retrospective review was conducted of 40 patients who underwent lymphangiography and TDE for persistent postoperative chyle leaks following TDL between January 2017 and May 2024. Patients were classified as low output (≤ 1000mL/day) or high output (> 1000mL/day) based on maximal daily drain output prior to TDE. Lymphangiographic findings, technical success, and clinical outcomes were analyzed. Clinical success was defined as an 80% or greater decrease in daily drain output or drain removal within one week. RESULTS: Lymphangiography demonstrated complete TDL - defined as abrupt occlusion of the thoracic duct at the ligation site without contrast passage - in 37 patients (92.5%). Among 37 patients with complete TDL, contrast leakage below the ligation site was identified in 15 (41%). Cisterna chyli or thoracic duct cannulation was successful in 38 patients (95%). Overall clinical success of TDE was 62.5% (25/40). Post-procedure day 1 drain output was significantly lower in successful cases (324 mL vs 852 mL; p = 0.0003) and time to drain removal was shorter in the low output group (7.5 vs 14.5 days; p = 0.024). No procedure-related adverse events occurred. CONCLUSIONS: In patients with persistent chylothorax after TDL, the thoracic duct is typically completely ligated and persistent leaks originate from lymphatic injury below the ligation site. Post-procedure day 1 drain output was associated with treatment response and may help guide timely decisions regarding adjunctive interventions.