A simplified classification and economical application of anterolateral thigh flap

Background: Anterolateral thigh (ALT) flaps have several anatomical variations and clinical uses. Here, a simplified classification and economical application are introduced. Methods: A total of 168 ALT flap reconstructions performed between January 2013 and December 2016 were reviewed. Vascular anatomy of the flaps was classified into 5 types: type I (single perforator from the transverse branch), type II (single perforator from the descending branch), type III (multiple perforators from the transverse branch), type IV (multiple perforators from the descending branch), and type V (multiple perforators from both branches). Furthermore, flaps harvested via preservation of the proximal perforator were compared with those that were not. Results: Vascular classification revealed that type IV (50.0%) and type V (32.1%) flaps were the most commonly used. Of these, 50.0% of type IV and 79.6% of type V were harvested as proximal-perforator-preserving distal ALT flaps. The proximal-perforator-preserving group had a smaller flap size (104.4 ± 84.3 cm² versus 145.9 ± 94.1 cm², p = 0.003), shorter reconstruction time (266.3 ± 76.1 min versus 302.0 ± 103.0 min, p = 0.013), and fewer donor-site complications (2.4% versus 13.3%, p = 0.009) than the traditional group, whereas the flap success rate was comparable (96.5% versus 96.4%) between them. Five cases received a second ALT flap from the same donor site after 3 failures and 2 metachronous defects. Conclusions: Multiple perforators in ALT flaps allow the harvesting of 2 ALT flaps from the same donor-site metachronously. Our classification and applications can improve efficiency while reducing donor-site morbidity.