Preoperative assessment of the perforators of the anterolateral thigh flap: a critical review

The anterolateral thigh flap is gaining widespread popularity as a workhorse in the reconstructive surgery of head and neck defects. The variation of the perforators is still a challenge in preoperative designing. The aim of this critical review is to introduce the current modalities used in perforators’ mapping of the anterolateral thigh flap and evaluate their strengths and weaknesses. Materials and methods The Web of Science database was used in this review. This review examined literatures that assess the accuracy, strengths and weaknesses of new techniques used in the preoperative assessment of anterolateral thigh flap perforators. Search terms included ‘anterolateral thigh flap’ in combination with ‘computed tomography angiography’, ‘handheld Doppler’, ‘colour duplex sonography’, ‘computed tomography-guided stereotaxy’ and ‘magnetic resonance angiography’. All literatures were found between 2002 and 2012 in English language. Results A total of 20 papers were reviewed according to the refined search. Although the handheld Doppler is non-invasive and portable, it often misidentifies or misses vessels, especially in evaluating small perforators, making this modality unreliable. Colour duplex sonography provides high spatial resolution of superficial perforators. Computed tomography angiography, computerised tomography-guided stereotaxy and magnetic resonance angiography provide the best three-dimensional images and have become the most advanced modalities used to assess the accurate anatomy of the donor site, of the anterolateral thigh flap. Conclusion Given the requirement to improve the outcome of anterolateral thigh flap reconstructive surgery, preoperative assessment of the perforators is essential. The ABC assessment system combined with colour Doppler/computed tomography angiography will facilitate an ideal individual assessment of this perforator flap. Introduction Since it was first introduced in 1984 by Song et al.1, the anterolateral thigh (ALT) flap is known as a versatile flap in reconstructive surgery because of its long vascular pedicle, pliable skin paddle and minimal donor site morbidity. In any case, locating the perforators is a critical step in flap design. In previous studies2, three cutaneous perforators of the ALT flap were identified in specific locations named perforators A, B and C from proximal to distal (the ABC system), and the experience seemed to suggest that the ABC system is reliable and can guide flap design without the need for preoperative imaging3. As the volume of the perforator flap reconstruction increases, the necessity to obtain the precise localization of the cutaneous perforators becomes much more urgent, and hence, more and more imaging modalities must be introduced. Until now, no adequate formal analyses of the accuracy and feasibility of the modalities used for preoperative imaging of ALT perforators, have been reported. Therefore, the main purpose of this critical review was to elucidate new techniques that have been introduced to locate perforators and to identify their size, origin and the pattern of their course (septocutaneous or myocutaneous). This review was also aimed at evaluating the accuracy, strengths and weaknesses of the modalities used in the preoperative assessment of ALT perforators. Materials and methods A literature search was undertaken using the Web of Science database. Topic searches were performed using the following terms: ‘anterolateral thigh flap’ in combination with ‘computed tomography angiography (CTA)’, ‘handheld Doppler’, ‘colour duplex sonography (CDS)’, ‘computerised tomography (CT)guided stereotaxy’ and ‘magnetic resonance angiography (MRA)’. The number of search results was further reduced by only including studies in the year range 2002–2012 and only those written in English language, after which, a manual filtration for relevance was performed. This retrospective review contains 20 literatures reporting patients who underwent reconstructive surgery with the ALT flap. The modalities used to assess the anatomical vasculature in the donor region can be broadly classified as: (a) CTA (n = 10), (b) colour Doppler sonography (n = 8), (c) CT-guided stereotaxy (n = 1) and (d) MRA (n = 1). The literatures were analysed to assess * Corresponding author Email: changfusun@hotmail.com Department of Oromaxillofacial–Head and Neck Surgery, Department of Oral and Maxillofacial Surgery, School of Stomatology, China Medical University, 117 North Nanjing Street, Heping District, Shenyang 110002, China On co lo gy & Re co ns tr uc tio n