Efficacy of the handheld Doppler in preoperative identification of the cutaneous perforators in the anterolateral thigh flap

Background: Preoperative localization of the cutaneous perforators is an important step in designing anterolateral thigh flaps. The purpose of this study was to examine the accuracy of two commonly used Doppler devices in locating these perforators. Methods: This study was conducted in 100 free anterolateral thigh flaps during a 2-year period. Cutaneous perforators of the anterolateral thigh flaps were localized in the clinic using the Huntleigh Mini Dopplex D-900 unit with an 8-MHz probe (Huntleigh Diagnostics Ltd., Cardiff, United Kingdom) and in the operating room just before surgery using the Koven ES-100X Mini Doppler unit with a 10-MHz sterile probe (Koven Technology, Inc., St. Louis, Mo.). The locations of Doppler signals and of the actual cutaneous perforators at surgery were plotted and compared. Results: One to three cutaneous perforators of the anterolateral thigh flap were consistently found at specific locations; they were named perforators A, B, and C from proximal to distal. Perforators A, B, and C were present in 51, 89, and 62 cases, respectively, at surgery and were approximately 5 cm apart. The sensitivities and specificities in detecting perforator B were 100 percent and 0 percent, respectively, for the Huntleigh Doppler unit, and 91 percent and 55 percent for the Koven unit. The Doppler signal was within I cm of the actual perforator B location in 74 percent and 70 percent of the flaps with the Huntleigh and Koven units, respectively. The accuracy of Doppler examination decreased as body mass index increased. Conclusions: Preoperative handheld Doppler examination is not always accurate and should be used with caution in flap design.