Preoperative perforator mapping of anterolateral thigh flaps using computed tomographic angiography and visual coordinate system for the reconstruction of head and neck defects

The anterolateral thigh (ALT) flap is a versatile workhorse flap for the reconstruction of head and neck defects; however, variations in the location of perforators are a significant concern. This prospective study proposes a rapid, effective, and convenient method for mapping the location of sizeable perforators on the curved thigh skin surface using the visual coordinate system in computed tomographic angiography (CTA) images. Fourteen patients suffering from defects after head and neck carcinoma resection underwent CTA prior to ALT flap reconstruction at the Department of Otolaryngology-Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, from January 2018 to August 2021. Using sterile gauze swab developing lines pasted on the patients' thighs, we established a coordinate system visualized both in CTA images and the thighs. The perforator information was then compared between the CTA and intraoperative findings. Twenty-one perforators were detected on CTA in the designed flaps, which were also confirmed during the operation with a visual pulse. The course and source of the perforators were consistent with the intraoperative findings. The distances of perforator coordinate points between CTA and intraoperative findings were