Inverse relationship of the anterolateral and anteromedial thigh flap perforator anatomy

Background  When anterolateral thigh (ALT) perforators are inadequate, exploration of the contralateral thigh or a new flap may be required. If the anteromedial thigh (AMT) perforators were useable in these instances, harvest could proceed from a single donor site. The purposes of this study were to define the AMT perforator anatomy and examine the relationships between the AMT and ALT perforators. Methods  A total of 100 consecutive thighs were explored. The ALT and AMT perforator size and number were documented. The relationship between ALT and AMT size and number was examined using Fisher exact test, logistic regression, and linear regression. Results  The main blood supply to the AMT flap was the rectus femoris branch (RFB) off the descending branch of the lateral circumflex femoris artery. AMT perforators were only present in 51% of the thighs and most likely a single perforator near the midpoint and 3.2 cm medial to the line connecting the anterior superior iliac spine and the patella (perforator B location). Patients with one or fewer ALT perforators had fourfold increased chance of an AMT perforator. Patients with small or no ALT perforators usually had a large AMT perforator. After assigning numeric values to perforators based on size, lower ALT perforator scores were significantly related to higher AMT scores. Conclusion  The RFB is the main vascular pedicle of the AMT flap. There is an inverse relationship between size and number of ALT and AMT perforators: when ALT perforators are inadequate, AMT perforators are typically useable.