The Anterolateral Thigh Flap

The anterolateral thigh (ALT) flap was first described by Sing et al. in 1984 and is a perforator fasciocutaneous flap. In recent decades, it has become the most commonly performed flap for reconstruction of the head and neck, extremity, trunk, and even perineum. Its popularity is mainly due to its long pedicle, versatility in flap design, reliable blood supply, and its relative standardization of operative technique. In our practice, it has become the workhorse flap when a free tissue transfer is needed for reconstruction of defects of the lower third of the leg. Its close proximity to other flaps and its unique vascular anatomy allows it to be harvested with muscle (tensor fascia lata or vastus lateralis) or tendon (iliotibial band). Furthermore, it can be used as a flow-through flap when distal revascularization is needed. Finally, the ALT flap can be used as a neurotized flap and provide sensation in critical areas (such as the heel of the foot) using the lateral femoral cutaneous nerve. The ALT flap can be harvested in a suprafascial or subfascial fashion, depending on the reconstructive needs and the surgeon’s experience. The ALT flap may be small or large, depending on the reconstructive needs. While some flaps may be thick, they can safely be thinned. When this is done, we prefer to thin the flap in situ, with the pedicle dissected but not ligated and under the guidance of real-time fluorescence imaging to assist with safe debridement. The donor site can sometimes be primarily closed; however, often, a split thickness skin graft is needed. The donor site may be cosmetically unacceptable for female patients and some degree of paresthesias in the lateral thigh can be encountered.