Technical Performance and Clinical Utility of Indocyanine Green Thoracic Duct Lymphography During Esophagectomy: A Systematic Review and Meta-analysis.

BACKGROUND: Postoperative chylothorax is an uncommon but serious complication of esophagectomy, usually caused by thoracic duct injury. Indocyanine green (ICG) near-infrared fluorescence lymphography has been used to improve intraoperative identification of the thoracic duct. This systematic review and meta-analysis evaluated its technical performance, safety, and effect on postoperative chyle leak. METHODS: Clinical studies of ICG-guided thoracic duct visualization during primary esophagectomy were included. The primary outcome was successful visualization of thoracic duct. Secondary outcomes included route-specific success, postoperative chyle leak, changes in operative management, and adverse events. Random-effects meta-analysis of proportions and risk ratios was performed. Risk of bias was assessed with ROBINS-I and the Joanna Briggs Institute checklist. RESULTS: Sixteen studies were included. Thoracic duct visualization, a primary technical endpoint, was achieved in 656/702 patients (pooled rate 94.8%, 95% CI 87.6-97.9%; I² = 66.6%). Visualization was higher with intranodal than subcutaneous administration (98.2% vs 92.9%; subgroup p = 0.029). Across 16 cohorts, chyle leak occurred in 22/853 patients (2.58%). In five comparative studies, ICG did not significantly reduce chyle leak (RR 0.61, 95% CI 0.21-1.80; p = 0.277) or reintervention (RR 0.97, 95% CI 0.36-2.65; p = 0.94). No clinically significant adverse events occurred in 653 patients; comparative studies had serious risk of bias. CONCLUSIONS: ICG fluorescence lymphography provides highly reliable intraoperative visualization of the thoracic duct and appears safe. However, visualization represents a technical rather than patient-important clinical endpoint, and the available evidence does not demonstrate a reduction in postoperative chyle leak or reintervention. ICG should therefore be regarded as an anatomical-navigation tool whose clinical effectiveness remains to be established in adequately powered prospective comparative studies.