Near-Infrared Laser-Assisted Indocyanine Green Imaging for Optimizing the Design of the Anterolateral Thigh Flap

Objective: The anterolateral thigh flap is a versatile flap that can be used in a free or pedicled fashion. Because of the large amount of potential soft tissue, low donor site morbidity, and long pedicle lengths, many researchers consider it to be the perfect free flap. However, dissection of this and other perforator flaps can become an arduous experience with learning curves to overcome. Near-infrared laser angiography using indocyanine green provides a useful adjunctive tool to more predictably assess direct perforator perfusion zones. Laser-assisted angiography with SPY-Q analysis gives live localization of the flap's dominant perforator perfusion zones while quantifying the relative tissue perfusion for immediate skin paddle design. Methods: Fifteen patients with head and neck cancer defects were reconstructed with a free anterolateral thigh flap using laser-assisted near-infrared indocyanine green perforator mapping. The mid-point of a line between the anterior superior iliac spine and the patella was determined and the laser was centered over this. Indocyanine green (12.5 mg) was injected intravenously and fluorescence patterns were recorded. Optimal perforators were chosen using real-time imaging and SPY-Q analysis software. The anterolateral thigh skin paddle was centered over perforators based on best relative perfusion values. The hand-held Doppler was not used to identify perforators. All flaps were elevated in standard fashion. Patient demographics, defect characteristics, reconstructive techniques, and clinical outcomes were assessed. Results: All 15 free flaps were raised with the assistance of laser-assisted angiography. Cutaneous Doppler did not aid in the design of the skin paddle. There was only 1 flap loss due to venous congestion. All donor defects were closed primarily without the need for a skin graft. Conclusions: Laser-assisted indocyanine green angiography using SPY-Q analysis software provides robust, intraoperative, objective data to optimize anterolateral thigh skin paddle design while potentially minimizing patient morbidity. Future studies will be needed to further evaluate the use of this new technology.