Revisiting Vascular Supply of the Rectus Femoris and Its Relevance in the Harvest of the Anterolateral Thigh Flap

Introduction The anterolateral thigh flap is one of the commonest soft tissue flap performed today. The rectus femoris is dominantly supplied by the vascular pedicle which takes off from the same source artery that is harvested with the anterolateral thigh flap. Therefore, the blood supply of the rectus femoris may potentially be compromised when harvesting the anterolateral thigh flap. This study revisits the blood supply of the rectus femoris in the light of recent advances in the understanding of the vascular anatomy of the anterolateral thigh. Materials and methods From January 2010 to June 2011, a prospective intraoperative observational study was performed in 50 consecutive anterolateral thigh flaps, noting the dimensions and locations of (1) the descending branch, (2) the presence of the oblique branch of the lateral circumflex femoral artery, and (3) the number and size of the muscle branches supplying the rectus femoris. Temporary selective occlusion with microvascular clamps was performed to evaluate the dominance of the blood supply to the muscle. Flap harvest was then completed as planned. Results The oblique branch was noted to be present in 23 (46%) of 50 patients. Of these, 21 (91%) of 23 of oblique branches supplied a large muscle branch to the rectus femoris. When the descending branch alone was present, occluding the dominant pedicle will usually compromise the blood supply to the muscle. In situations where 2 large muscle branches arise from the descending and oblique branches, occlusion of either pedicle did not affect the circulation of the rectus femoris, demonstrating codominance in this situation. Conclusions The vascularity of the rectus femoris can be classified as either a type A or B. Type A rectus femoris is the classic pattern with a single dominant pedicle from the descending branch. Type B rectus femoris is seen when an oblique branch supplies a codominant pedicle to the muscle. The implication of this anatomy is that in a type B rectus femoris, one of the 2 muscle branches can be safely ligated to increase the pedicle length when harvesting of the anterolateral thigh flap, without compromising the vascularity of the muscle.