Intraoperative indocyanine green versus clinical assessment for prevention of free flap failure: A systematic review and meta-analysis

Both total and partial flap failure are complications of free-tissue transfer surgery associated with significant morbidity, reoperation burden, and healthcare costs. This meta-analysis evaluates whether intraoperative indocyanine green fluorescence angiography (ICG-FA) differs from clinical assessment in preventing total and partial flap loss in free flap surgery.

MEDLINE, Embase, Cochrane, Scopus, and Web of Science databases were searched from inception to 17th February 2026. Key search terms included free flap, free tissue transfer, indocyanine green, and fluorescence angiography. Sensitivity analysis was carried out using a leave-one-out approach. Risk of bias was assessed using ROBINS-I for non-randomised studies, and Cochrane RoB-2 for randomised trials. The analysis was pre-registered on PROSPERO (CRD420261309021).

Eight studies were included in the final analysis, totalling 2179 free-flap procedures, 1098 of which were controls. Controlled studies comparing intraoperative ICG-FA to clinical assessment produced 90% reduction in odds for partial failure (OR 0.10, 95% CI: 0.04, 0.26; p < 0.01), 41% reduction for total failure (OR 0.59, 95% CI: 0.35, 0.97; p = 0.04), and 53% reduction for requirement of reoperation (OR 0.47, 95% CI: 0.25, 0.88; p = 0.02).

Intraoperative ICG-FA was associated with reduced odds of partial and total flap loss, as well as reoperation, compared with conventional clinical assessment. These findings suggest that ICG-FA may therefore represent a valuable adjunct in free flap surgery. Further high-quality prospective trials will be required to better elucidate the true magnitude of effect of ICG-FA in free flap surgery and clarify its role in contemporary microsurgical practice.