Fluorescent Navigation Surgery for Gastrointestinal Tract Cancers: Detection of Sentinel Nodes, Tumor Tattooing, and Harvesting of Lymph Nodes

Abstract

The applications of indocyanine green (ICG) fluorescence imaging (IFI) for fluorescent-guided surgery have been expanding. Here we assessed the use of IFI in gastrointestinal tract surgeries. We first evaluated the feasibility of sentinel lymph node (SLN) mapping guided by IFI in gastrointestinal cancers. Twenty-two gastric cancer patients and 26 colorectal cancer patients who had undergone standard surgical resection were enrolled. The SLN detection rate in our preliminary study was 90.9 % and the mean number of SLNs was 3.6 in the gastric cancer patients, and the corresponding values in the colorectal cancer patients were 88.5 % and 2.6. Among the gastric cancer patients, the accuracy was 88.9 % and the false-negative rate was 33.3 %. Secondly, we assessed the efficacy of a new method for tattooing the tumor location using IFI instead of India ink. We succeeded in the ICG marking of early-stage stomach cancer and colon cancer, and our results may lead to the establishment of a new marking procedure instead of the conventional India ink and clipping methods. Lastly, we evaluated whether an IFI method of harvesting lymph nodes (LNs) from resected specimens could improve the accuracy of LN staging. ICG fluorescence-labeled LNs were found even though the ICG solution was injected ex vivo. The IFI method thus improved the LN harvest from resected specimens. This method will provide precise evaluations of the pathological status of LNs.