Comparing Intraoperative Indocyanine Green Fluorescence Imaging With Standard Clinical Assessment for Flap Perfusion in Head and Neck Reconstruction: A Randomised Controlled Trial (VISION Trial)

The VISION Trial is a prospective, multicentre, open-label, parallel-group randomised controlled trial comparing intraoperative indocyanine green (ICG) fluorescence angiography with standard clinical assessment for flap perfusion in head and neck free flap reconstruction.

Free flap reconstruction is an essential component of complex head and neck reconstruction, but flap survival depends on adequate microvascular perfusion. Conventional intraoperative assessment methods, including inspection of flap colour, capillary refill, tissue turgor, bleeding upon needle prick, and Doppler examination, provide indirect assessment of perfusion and may be unreliable in some situations.

ICG fluorescence angiography enables real-time visualisation of arterial inflow and venous outflow using near-infrared fluorescence imaging. Retrospective studies have suggested that ICG angiography may reduce rates of partial flap loss and flap-related re-exploration, but high-quality prospective randomised evidence remains limited.

A total of 244 adult patients undergoing microvascular free flap reconstruction for oncologic, trauma, or benign head and neck defects at participating Swedish centres will be included. Participants will be randomised to either standard clinical assessment alone or standard clinical assessment supplemented with intraoperative ICG fluorescence angiography.

In the intervention group, ICG angiography will be performed intraoperatively using near-infrared fluorescence imaging systems after administration of intravenous indocyanine green (Verdye®). Quantitative perfusion analysis will also be performed using SPY-Q software.