Intraoperative indocyanine green fluorescence angiography for flap perfusion assessment in head and neck oncological reconstruction: a systematic review

Objectives To evaluate the clinical utility of intraoperative indocyanine green fluorescence angiography (ICG-FA) for perfusion assessment in head and neck oncological flap reconstruction and its association with outcomes and intraoperative decision-making. Materials and Methods A PRISMA-compliant systematic review, searched MEDLINE, Embase, and CENTRAL from inception to 19 February 2026. Eligible studies included adults undergoing head and neck oncological resection with free or pedicled flap reconstruction using intraoperative ICG-FA. Primary outcomes were return to theatre, partial flap necrosis, total flap loss, and flap salvage. Secondary outcomes included fistula, wound dehiscence, infection, and intraoperative decision impact. Two reviewers independently performed study selection, data extraction, and risk of bias assessment. Owing to heterogeneity, findings were synthesised narratively. Results Ten observational studies were included, comprising 469 ICG-assessed flaps in 463 patients; two comparative studies also contributed 306 non-ICG comparator flaps. Most reconstructions were free flaps (90.6%). Re-exploration occurred in 12.4% (56/450) of ICG-assessed flaps, partial flap necrosis in 4.8% (4/83), and total flap loss in 3.8% (16/424). Salvage was achieved in 73.3% (33/45) of compromised flaps. Intraoperative management changed in 12.8% (12/94) of flaps. Risk of bias was significant in both comparative studies and moderate across the non-comparative series. Conclusion ICG-FA appears to be a useful adjunct to intraoperative perfusion assessment, with the clearest potential benefit in flap salvage, flap loss, and operative decision-making. However, the evidence base is limited by observational study design, heterogeneity, and risk of bias. Prospective comparative studies using standardised protocols are needed before routine adoption can be recommended.