The FLARE intraoperative near-infrared fluorescence imaging system: a first-in-human clinical trial in perforator flap breast reconstruction.

Background: The ability to determine flap perfusion in reconstructive surgery is still primarily based on clinical examination. In this study, the authors demonstrate the use of an intraoperative, near-infrared fluorescence imaging system for evaluation of perforator location and flap perfusion.
Methods: Indocyanine green was injected intravenously in six breast cancer patients undergoing a deep inferior epigastric perforator flap breast reconstruction after mastectomy. Three dose levels of indocyanine green were assessed using the fluorescence-assisted resection and exploration (FLARE) imaging system. This system uses light-emitting diodes for fluorescence excitation, which is different from current commercially available systems. In this pilot study, the operating surgeons were blinded to the imaging results.
Results: Use of the FLARE system was successful in all six study subjects, with no complications or sequelae. Among the three dose levels, 4 mg per injection resulted in the highest observed contrast-to-background ratio, signal-to-background ratio, and signal-to-noise ratio. However, because of small sample size, the authors did not have sufficient power to detect statistical significance for these pairwise comparisons at the multiple-comparison adjusted type I error of 0.017. Six milligrams per injection provided a similar contrast-to-background ratio but also a higher residual background signal.
Conclusion: Based on this pilot study, the authors conclude that near-infrared assessment of perforator flap breast reconstruction is feasible with a light-emitting diode-based system, and that a dose of 4 mg of indocyanine green per injection yields the best observed contrast-to-background ratio compared with a dose of 2 or 6 mg for assessment of flap perfusion.