Near-infrared mapping with indocyanine green is associated with an increase in oncological margin length in minimally invasive segmentectomy

BACKGROUND: Near-infrared fluorescence mapping with indocyanine green dye is a recent advancement in minimally invasive segmental resection. This technique has not yet been reproduced, validated, or objectively evaluated in a large prospective case series. We hypothesized that near-infrared fluorescence mapping is associated with an increased oncological margin distance from the tumor, over and above the best judgment of the surgeon. METHODS: This was a phase 2 prospective cohort trial in patients who are undergoing robotic segmentectomy for lung tumors <3 cm. The predicted intersegmental plane was first identified by consensus between 2 thoracic surgeons. The true plane was then mapped by indocyanine green injection. A 7-item binary rating scale was used for the evaluation of feasibility, reproducibility, and added oncological margin distance from the tumor. The margin distance between the tumor and the true plane was compared with the margin distance between the tumor and the predicted plane. RESULTS: Fifty-three patients were enrolled between September 2016 and May 2018 and 31 patients (58.4%) received the planned operation with indocyanine green mapping. In 74.2% of cases (23 out of 31), a score of 7 out of 7 was achieved, indicating the true intersegmental plane identified by indocyanine green mapping was different than the predicted plane identified by the surgeon. In 61.2% (19 out of 31) of those cases, the mean additional margin distance from the tumor to the staple line attributable to the indocyanine green mapping was 2.41 ± 1.6 cm. The overall complication rate was 18.5% (10 out of 53) and there were no deaths. CONCLUSIONS: Near-infrared fluorescence mapping in robotic segmentectomy is associated with increased oncological margin length, over and above the best judgment of the surgeon, in the majority cases where it is used.