Free Anterolateral Thigh Flaps for Reconstruction of Head and Neck Defects
This chapter describes another source of tissue for your reconstructive efforts in the head and neck area. The solution is especially attractive, inasmuch as it does not require changing the position of the patient.
The anterolateral thigh flap is based on the septocutaneous or muscle perforators of the lateral descending branch of the lateral circumflex femoral system. It is useful for reconstruction of defects in the head and neck and in the extremities.
This flap is suitable for coverage of defects in the head and neck regions, such as the oral floor with or without tongue and hypopharyngeal defects, and also the cervical esophagus with the anterior cervical wall (1). It is also suitable for reconstruction of scalp defects. Even in infected cranial full-thickness defects involving the dura, one-stage reconstruction is possible using an anterolateral thigh fasciocutaneous flap because the dural defect can be replaced with the vascularized fascia lata. The fasciocutaneous flap is also suitable for the repair of large, full-thickness defects of the lip. Instead of the oral orbicular muscle, the vascularized tensor fascia lata can be used to suspend the lower or upper lip. In obese patients, the flap can be made thinner with primary defatting (1).
The main advantage is that, with the use of the vascular system of this flap, massive complex defects in the head and neck can be easily reconstructed in one stage with combined “chimeric” flaps with the same vascular source. The flap can be combined with other flaps or tissue (chimeric combined flap), such as the paraumbilical flap (rectus abdominis musculocutaneous flap), vascularized iliac bone or fibula, rectus femoris muscle, or sartorius muscle (2). In addition, this flap can be connected with other adjacent flaps (“mosaic” flaps), such as the connected anterolateral thigh-groin flap and/or anterolateral thigh-medial thigh flap (3).
The lateral circumflex femoral system is composed of three main branches: the ascending branch, which passes through the intermuscular space between the sartorius and vastus lateralis muscles and terminates in the outer cortex of the iliac bone; the transverse branch, which terminates in the tensor fasciae latae muscle; and the (lateral) descending branch, which runs downward through the intermuscular space between the rectus femoris and the vastus lateralis muscles and finally terminates in the vastus muscle near the knee joint. The perforator of the anterolateral thigh flap usually is derived from the transverse branch or the descending branch, and the proximal perforator is situated around the proximal third of the thigh through the lateral longitudinal line of the thigh. Usually, a few cutaneous perforators are found passing through the intermuscular septum or the vastus lateralis muscle. Even in cases with no septocutaneous perforators, there are cutaneous perforators penetrating the vastus lateralis muscle (1, 2, 3, 4, 5, 7, 8) (Fig. 144.1).