Intraoperative indocyanine green fluorescence angiography in colorectal surgery to prevent anastomotic leakage: A single-blind phase III multicentre randomized controlled trial (FLUOCOL-01/FRENCH 21/GRECCAR 19 intergroup trial).

AIM: Anastomotic leak (AL) is a major problem in colorectal surgery, and its prevention is crucial for patient safety. The scientific literature shows that optimal anastomotic perfusion is essential for anastomotic healing. However, in cases of left colon or rectal cancer requiring high vessel ligation for oncological reasons, anastomotic blood supply relies mainly on the pericolic arterial arcades. Consequently, assessing anastomotic perfusion using intraoperative fluorescence angiography with indocyanine green might be relevant to reduce the risk of AL. Although evidence of its positive impact on the risk of AL is growing in the literature, most studies are descriptive prospective cohorts or retrospective comparative series with controversial findings. Furthermore, no other studies specifically address left-sided colon or high rectal tumours. FLUOCOL-1 is a large multicentre randomized controlled trial (RCT) that aims to demonstrate that assessing anastomotic perfusion using intraoperative fluorescence angiography with indocyanine green will reduce ALs in left-sided or high anterior resections with intraperitoneal anastomosis METHOD: FLUOCOL-1 is a French multicentre, single-blind, randomized, two-arm, phase III superiority clinical trial. Patients will be randomized in a 1:1 ratio to either the intervention group (FLUO+) or the control group (FLUO-). A total of 1010 patients will be randomized. The primary endpoint is the occurrence of an AL within 90 days postsurgery. AL is defined as any anastomotic dehiscence with leakage into the pelvic cavity diagnosed by imaging or surgical exploration, or any isolated pelvic organ-space infection with no evidence of fistula, as defined by the International Study Group of Rectal Cancer.

DISCUSSION: Prevention of AL is one of the most important questions to be addressed in colorectal surgery. The FLUOCOL-1 multicentre RCT described herein aims to demonstrate that assessment of anastomotic perfusion using intraoperative fluorescence angiography with indocyanine green will reduce ALs in certain resections with intraperitoneal anastomosis.