Application of indocyanine green angiography in repair of facial soft tissue defect using superficial temporal artery based forehead flap

Abstract

To explore the feasibility of using indocyanine green angiography in mapping the superficial temporal vessels and assisting design and harvesting of the superficial temporal artery based forehead flap. A clinical data of 14 patients with facial soft tissue defects repaired with superficial temporal artery based forehead flaps between October 2015 and November 2022 was retrospectively analyzed. There were 9 males and 5 females with a median age of 9.5 years (range, 3-38 years). The forehead flaps were used to reconstruct facial soft tissue defects following excision of facial scar (8 cases) or congenital melanocyte nevus (6 cases). The size of defects ranged from 3 cm×2 cm to 24 cm×9 cm. Before operation, the indocyanine green angiography was used to map the superficial temporal artery and vein, and to analyze the relationship of the arteries and veins. The forehead flaps with unilateral superficial temporal fascia as the pedicle was transferred to repair the small facial defect in 2 cases. The facial pedicle contained the frontal branch of the superficial temporal artery and 2 cm of the superficial temporal fascia around the vessel, and the tiny accompanying vein of the frontal branch of the superficial temporal artery was used as the outflow of the flap. The forehead flaps with the skin pedicle including bilateral or unilateral superficial temporal fascia and the overlying skin was pre-expanded and transferred to repair the large facial defect in 12 cases. The skin pedicle contained the frontal branch of superficial temporal artery and one of main branches of superficial temporal vein. Among the 12 cases, the frontal branch of superficial temporal vein was used as the outflow in 4 cases, and the parietal branch was used as the outflow in 8 cases. The size of the flaps ranged from 3 cm×2 cm to 30 cm×13 cm. The skin pedicles were divided at 3 weeks after the flap transfer. Indocyanine green angiography could clearly showed the course and branching of the superficial temporal artery and vein. Individual differences existed in the location where the frontal branch of the superficial temporal artery entered the forehead. The superficial temporal vein had great variability and did not follow the artery. One patient had expander-related complication, which resulted in 3-cm flap necrosis. The necrotic tissue was debrided and repaired with skin grafting. The other flaps totally survived and the incisions healed by first intention. All patients were followed up 2-24 months, with a median of 11.5 months. The color, texture, and thickness of the flaps matched well with those of recipient sites. Hypertrophic scar was not observed in recipient or donor site. All patients were satisfied with the reconstructive outcomes. Indocyanine green angiography can clearly visualize the course and the branches of the superficial temporal arteries and veins, which can help surgeons understand the position, distribution, and concomitant relationship of the superficial temporal vessels, and make a rational surgical plan of the forehead flap.