Takeo Nitta, Yuma Ebihara, Hironobu Takano, Saseem Poudel, Hideyuki Wada, Soichi Murakami, Toshiaki Shichinohe, Satoshi Hirano
Fiber-optic near-infrared fluorescence spectroscopy using ICG was feasible for the intraoperative acquisition of single-site TICs at the planned anastomotic site before and after retrosternal reconstruction. Descriptive changes were observed mainly in inflow-related parameters. However, this study did not establish measurement accuracy, diagnostic performance, or clinical utility, and the numerical values should not be interpreted as reference ranges or clinically actionable thresholds.
BACKGROUND: Adequate perfusion at the planned anastomotic site is important during gastric conduit reconstruction after esophagectomy. However, objective intraoperative assessment remains challenging. This pilot study evaluated the feasibility of fiber-optic near-infrared fluorescence spectroscopy using indocyanine green (ICG) and descriptively characterized local semi-quantitative time-intensity curve (TIC) changes before and after retrosternal gastric conduit elevation.
METHODS: This single-center retrospective study included eight patients who underwent minimally invasive esophagectomy with narrow gastric conduit reconstruction via the retrosternal route. ICG fluorescence was continuously recorded for 5-10 min at the same suture-marked planned anastomotic site before conduit formation and after retrosternal elevation using a near-infrared fluorescence spectroscopy system equipped with a fiber-optic measurement probe. One recording was obtained at each time point. The TIC parameters were calculated post hoc and summarized descriptively.
RESULTS: TICs were successfully obtained at both time points in all patients. The median slope (rise) decreased from 0.147 to 0.024 AU/sec, with decreases observed in six of eight patients. The median Fmax decreased from 9.37 to 8.03 AU, although individual changes were variable, whereas Tmax, plateau intensity, and slope (decay) showed relatively limited changes.
CONCLUSION: Fiber-optic near-infrared fluorescence spectroscopy using ICG was feasible for the intraoperative acquisition of single-site TICs at the planned anastomotic site before and after retrosternal reconstruction. Descriptive changes were observed mainly in inflow-related parameters. However, this study did not establish measurement accuracy, diagnostic performance, or clinical utility, and the numerical values should not be interpreted as reference ranges or clinically actionable thresholds.