Preoperative assessment of anterolateral thigh flap cutaneous perforators by colour Doppler flowmetry.

An anterolateral thigh flap is very useful in head and neck reconstruction because of its long and large-caliber vascular pedicle, large skin territory and elevation simultaneous with tumour resection. However, the number and locations of cutaneous perforators vary individually, and thus, it is not widely used because flap elevation is often complicated and time-consuming owing to unexpected anatomical variations. To overcome this disadvantage, we assessed the number and locations of cutaneous perforators preoperatively by colour Doppler flowmetry. These data were compared with the intraoperative anatomical findings and their reliability evaluated. A total of 48 cutaneous perforators were found by preoperative colour Doppler flowmetry scanning of 17 anterolateral thigh flaps. All the perforators except two were found intraoperatively. Doppler scanning failed to detect four perforators. Colour Doppler flowmetry assessment therefore has a 92% true-positive rate and a 95.8% positive predictive value. All the flaps except one included multiple perforators, and sufficient blood circulation was observed in all cases. No flaps were unexpectedly changed to anteromedial thigh flaps or contralateral anterolateral thigh flaps because of inappropriate cutaneous perforators or the absence of perforators. Though this investigation is relatively time-consuming (30-40 min) and requires skill, it is very useful for preoperative flap planning and increases the reliability and safety of elevating an anterolateral thigh flap.