Colorectal anastomotic safety assessment using ICG fluorescence and flexible endoscopy (COLOSSEUM): a global survey of 1367 surgeons

Aim: Anastomotic leakage remains a major complication in colorectal surgery. Indocyanine green (ICG) fluorescence and flexible endoscopy (FE) are used to assess perfusion and anastomotic integrity. We aimed to evaluate global practice patterns and intersurgeon variability to inform structured recommendations. Methods: This international survey was conducted between April and November 2024 within the EAES Rising Stars Academy 2023–2024. In a Delphi-like process, 53 questions addressing surgeon characteristics, institutional practice, and the use of ICG and FE were developed and distributed worldwide. Results: A total of 1367 respondents from 80 countries participated (mean age 64 ± 10 years). ICG was available at 76% of institutions, and 67% of surgeons reported using it. Timing varied: before transection 40%, after transection 7%, before anastomosis 17%, after anastomosis 25%, and both before and after 11%. A fixed dose was used by 71% and weight-based dosing by 29%. FE was performed by 51% of surgeons, with 23% reporting routine intraoperative use. Key barriers included gastroenterologist-led practice (28%), reliance on alternative techniques (20%), and lack of training (19%). Substantial variability was observed across all domains. Conclusions: This survey revealed significant heterogeneity in the use of ICG and FE in colorectal surgery. Although ICG is more widely implemented, both techniques lack standardized protocols. Moreover, FE adoption remains limited by training and access. Training should be enhanced and could represent a key area of focus for future EAES programs.