Background
Anastomotic leak is a serious complication in colorectal surgery. Indocyanine green fluorescence angiography (ICGFA) is an adjunctive digital method of assessing bowel perfusion intraoperatively. We assessed whether ICGFA use during surgery reduces postoperative anastomotic leak exclusively using data from randomised controlled trials (RCTs).
Methods
In this systematic review and meta-analysis, we searched PubMed, ScienceDirect, Scopus, Web of Science, Embase, and the Cochrane Collaboration databases from inception to July 19, 2025, for English-language RCTs comparing additive intraoperative ICGFA with standard surgeon perfusion assessment alone in patients undergoing colorectal resection with primary anastomosis according to prespecified criteria and PRISMA guidelines. Summary-level data were extracted by two reviewers. The primary outcome was overall anastomotic leak rate. The Jadad scale (Oxford quality scoring system) was used to assess trial quality, the Cochrane Risk of Bias (RoB 2) tool for RCTs was used to assess risk of bias, and GRADE was used to assess strength of evidence. Meta-regression and trial sequential analyses were performed. This study is registered with PROSPERO, CRD420250652639.
Findings
719 records were initially identified, with 387 remaining after screening and 184 sought for full eligibility screening, of which nine were eligible RCTs (with 4754 patients) for analysis. ICGFA significantly reduced overall anastomotic leak (risk ratio 0·66 [95% CI 0·56–0·78], p<0·0001; number needed to treat [NNT]=24), with trial sequential analysis showing that the required information size (2183) was exceeded overall. ICGFA reduced both anastomotic leak requiring intervention (risk ratio 0·73 [95% CI 0·60–0·89], p=0·0020; NNT=39) and anastomotic leak not requiring intervention (0·48 [0·31–0·72], p=0·0004, NNT=35). Significant benefit was observed for left-sided resections (risk ratio 0·62 [95% CI 0·51–0·74], p<0·0001; NNT=19), rectal resections (0·62 [0·51–0·76], p<0·0001; NNT=19), and low anterior resections (0·62 [0·48–0·79], p<0·0001; NNT=13), in which the required information size was also exceeded, but not for right-sided resections. In the meta-regression analysis, among all tested covariates, only patient BMI significantly modified the ICGFA treatment effect, with an increasing protective effect with increasing BMI (coefficient –0·0153 [95% CI –0·0251 to –0·0056], p=0·0020). Evidence was graded as high certainty for overall, left-sided, rectal, asymptomatic, and 30-day anastomotic leaks, and moderate certainty for clinically significant anastomotic leak.
Interpretation
Intraoperative use of ICGFA reduces anastomotic leak rates in left-sided and rectal colorectal resections. Given the evidence available now, further general efficacy trials are no longer required and research should shift to implementation and defined targeted subgroup ICGFA role definition (ie, in non-rectal left-sided resections).
CORE (COnnecting REpositories)
CORE (COnnecting REpositories)