Anatomical Variability of the Anterolateral Thigh Flap Perforators: Vascular Anatomy and Its Clinical Implications

Background: Anatomical variability of perforators of the anterolateral thigh flap has been reported. The authors introduce a classification based on the number, location, and origin of the cutaneous perforators to comprehensively illustrate their vascular patterns in hopes that unfavorable anatomical variations of the anterolateral thigh flap can be overcome in clinical applications. Methods: The authors enrolled and reviewed 110 anterolateral thigh flaps created between September of 2010 and January of 2013 for head and neck reconstruction after cancer ablation. The location of the perforators was defined by Yu's ABC system. Its corresponding origin from the descending or transverse branch of the lateral circumflex femoral artery was clarified by Shieh's vascular anatomical classification for the anterolateral thigh flap. Results: Of the 110 flaps, a single perforator(A or B or C) was observed in 20 flaps(18.2 percent), double perforators(A + B or B + C or A + C) were observed in 59 flaps(53.6 percent), and triple perforators(A + B + C) in 31 flaps(28.2 percent). The origin of perforators was the descending branch in 76 flaps(69.1 percent), the transverse branch in 10 flaps(9.1 percent), and both descending and transverse branches in 24 flaps(21.8 percent). The authors observed 16 vascular patterns. The most common type was double perforators, with perforators B and C originating from the descending branch [n = 40(36.4 percent)]. Conclusions: The clinical significance of each pattern is delineated, and surgical technical considerations are suggested according to flap requirements and types of vascular anatomy.