Real-time thoracic duct visualization in lung cancer surgery: feasibility of indocyanine green fluorescence imaging via inguinal lymph node injection.

BACKGROUND

Chylothorax from thoracic duct (TD) injury is a serious complication of lung cancer surgery. This study aimed to evaluate the feasibility of real-time TD visualization using indocyanine green (ICG) fluorescence imaging via inguinal lymph node injection during uniportal video-assisted thoracoscopic surgery (VATS) lobectomy, with the primary endpoint being the success rate of TD identification.

METHODS

In this retrospective feasibility study of 54 T1N0M0 non-small cell lung cancer (NSCLC) patients undergoing uniportal VATS lobectomy, ICG was injected into superficial (n=23) or deep (n=31) inguinal lymph nodes. The primary endpoint was the success rate of TD visualization; secondary endpoints included time to fluorescence appearance, signal-to-background ratio (SBR), chyle test positivity, chest tube duration, and hospital stay. Near-infrared imaging visualized the TD, assessing success rate, time-to-visualization, SBR, and chylothorax.

RESULTS

TD visualization was successful in 96.3% (52/54) of cases. While success rates were similar between groups, deep injection yielded marginally faster visualization and higher SBR. Imaging revealed TD anatomy and variations, particularly near right lymph node stations. Right-sided surgeries had a non-significantly higher chyle test positivity and longer chest tube duration.

CONCLUSIONS

Deep inguinal lymph node injection of ICG is a feasible approach for real-time TD visualization, with comparable outcomes to superficial injection. This technique may aid anatomical mapping and potentially help reduce iatrogenic TD injury, although direct evidence of clinical benefit requires further study.