ICG fluorescence imaging in colorectal surgery: a snapshot from the ICRAL study group
Authors: Baiocchi Gian Luca , Guercioni Gianluca , Vettoretto Nereo , Scabini Stefano , Millo Paolo , Muratore Andrea , Clementi Marco , Sica Giuseppe , Delrio Paolo , Longo Graziano , Anania Gabriele , Barbieri Vittoria , Amodio Pietro , Di Marco Carlo , Baldazzi Gianandrea , Garulli Gianluca , Patriti Alberto , Pirozzi Felice , De Luca Raffaele , Mancini Stefano , Pedrazzani Corrado , Scaramuzzi Matteo , Scatizzi Marco , Taglietti Lucio , Motter Michele , Ceccarelli Graziano , Totis Mauro , Gennai Andrea , Frazzini Diletta , Di Mauro Gianluca , Capolupo Gabriella Teresa , Crafa Francesco , Marini Pierluigi , Ruffo Giacomo , Persiani Roberto , Borghi Felice , de Manzini Nicolò , Catarci Marco 
Published: April 2021

Abstract
Background
Fluorescence-guided visualization is a recently proposed technology in colorectal surgery. Possible uses include evaluating perfusion, navigating lymph nodes and searching for hepatic metastases and peritoneal spread. Despite the absence of high-level evidence, this technique has gained considerable popularity among colorectal surgeons due to its significant reliability, safety, ease of use and relatively low cost. However, the actual use of this technique in daily clinical practice has not been reported to date.

Methods
This survey was conducted on April 2020 among 44 centers dealing with colorectal diseases and participating in the Italian ColoRectal Anastomotic Leakage (iCral) study group. Surgeons were approximately equally divided based on geographical criteria from multiple Italian regions, with a large proportion based in public (89.1%) and nonacademic (75.7%) centers. They were invited to answer an online survey to snapshot their current behaviors regarding the use of fluorescence-guided visualization in colorectal surgery. Questions regarding technological availability, indications and techniques, personal approaches and feelings were collected in a 23-item questionnaire.

Results
Questionnaire replies were received from 37 institutions and partially answered by 8, as this latter group of centers do not implement fluorescence technology (21.6%). Out of the remaining 29 centers (78,4%), fluorescence is utilized in all laparoscopic colorectal resections by 72.4% of surgeons and only for selected cases by the remaining 27.6%, while 62.1% of respondents do not use fluorescence in open surgery (unless the perfusion is macroscopically uncertain with the naked eye, in which case 41.4% of them do). The survey also suggests that there is no agreement on dilution, dosing and timing, as many different practices are adopted based on personal judgment. Only approximately half of the surgeons reported a reduced leak rate with fluorescence perfusion assessment, but 65.5% of them strongly believe that this technique will become a minimum requirement for colorectal surgery in the future.

Conclusion
The survey confirms that fluorescence is becoming a widely used technique in colorectal surgery. However, both the indications and methods still vary considerably; furthermore, the surgeons' perceptions of the results are insufficient to consider this technology essential. This survey emphasizes the need for further research to reach recommendations based on solid scientific evidence.