PPG vs. ICG in Gastrointestinal Resections

This randomized controlled trial compares a novel optical technique against the standard of care for assessing tissue perfusion in gastrointestinal surgery. Participants are randomized to receive either intraoperative imaging photoplethysmography (iPPG) or indocyanine green (ICG) fluorescence imaging. In the ICG group, the fluorescence data are comprehensively analyzed in two distinct ways: (1) Qualitative Assessment: real-time visual interpretation of the angiogram flow by the operating surgeon; and (2) Quantitative Assessment: software-based analysis of fluorescence kinetics (e.g., time-to-peak, maximum intensity) to generate objective perfusion parameters. The study aims to determine the agreement between the iPPG-based evaluations and both the qualitative and quantitative dimensions of the ICG standard.