Abstract
Anastomotic leakage (AL) is one of the most serious complications after colorectal surgery, contributing to increased postoperative illness, extended hospitalisation, and higher mortality. Intra-operative evaluation of bowel perfusion with indocyanine green fluorescence angiography (ICG-FA) has emerged as a promising technique to reduce this risk, but randomised evidence remains limited. A systematic review and meta-analysis was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. PubMed, Excerpta Medica database (Embase) via Ovid, Medical Literature Analysis and Retrieval System Online (MEDLINE) via Ovid, ScienceDirect, and ClinicalTrials.gov databases were searched for randomised controlled trials (RCTs) comparing ICG-FA to conventional visual assessment during elective colorectal resections with primary anastomosis. The primary outcome assessed was AL. Subgroup analyses were performed for left- and right-sided resections. Risk of bias was assessed using the Cochrane Risk of Bias 2.0 (RoB 2) tool. A meta-analysis was conducted using a random-effects model, and heterogeneity was assessed using the I² statistic. Certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Meta-analysis of seven RCTs involving 3,887 patients showed that ICG-FA significantly reduced anastomotic leak rates compared to standard visual assessment. The pooled odds ratio (OR) was 0.66 (95% CI: 0.53-0.82; p = 0.003), with no heterogeneity (I² = 0%). The estimated number needed to treat (NNT) to prevent one leak was 22. Subgroup analysis revealed a greater effect in left-sided resections (OR: 0.59; 95% CI: 0.46-0.75; p = 0.002; NNT = 18), with no significant benefit seen in right-sided cases (OR: 0.83; p = 0.35). ICG-FA reduces anastomotic leak risk in colorectal surgery, particularly in left-sided resections. Further high-quality RCTs are needed to strengthen current evidence.