Comparing Intraoperative Indocyanine Green Fluorescence Imaging With Standard Clinical Assessment for Flap Perfusion in Head and Neck Reconstruction (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.

The primary endpoint is partial flap loss requiring intervention within 30 days after surgery. Secondary endpoints include total flap loss, flap-related re-exploration under general anaesthesia, flap salvage, postoperative complications graded according to Clavien-Dindo classification, and the association between intraoperative SPY-Q perfusion values and flap outcomes.

No additional trial-specific postoperative visits are required. Outcomes will be assessed through structured chart review at 30 and 90 days postoperatively.

Inclusion criteria

• Age ≥18 years at the time of inclusion
• Scheduled to undergo microvascular free flap reconstruction as part of oncologic, trauma, or benign surgery in the head and neck area
• Ability to understand study information and provide written informed consent

Exclusion criteria

• Known allergy to indocyanine green or iodine
• Severe hepatic or renal impairment
• Confirmed or suspected pregnancy
• Breastfeeding