In colorectal surgery, assessment of the vascularization of the intestinal segments to be anastomosed by injection of indocyanine green (ICG) is one of the intra-operative measures to decrease the risk of anastomotic leak (AL). The aim of this evidence-based review was to evaluate the effectiveness and utility of this measure.

We conducted a comprehensive literature review in electronic databases (PubMed, Scopus, Cochrane Library), coupled with a manual search. Only randomized trials and meta-analyses were included. The primary outcome measure was clinical AL (Grade B and C according to the International Study Group of Rectal Cancer)

A total of eight randomized trials and three meta-analyses were included. The conclusions of the three meta-analyses consistently showed a reduction in the risk of AL (by one-third in the most recent meta-analyses). However, the conclusions of the eight trials (especially those with the larger sample sizes) were discordant regarding colonic surgery (excluding rectal resection). In subgroup analysis, recent trials showed no difference in AL in favor of ICG for right colectomy, and data on left colonic or rectal surgery, although discordant, suggested that the benefit of ICG, although not statistically significant, was clinically relevant in the majority of studies.

According to currently available evidence, the use of ICG does not appear to be useful for right colectomies. However, the usefulness of ICG in left-sided colectomies and rectal resections is probable, although not formally proven.