Reliability and Safety of Super-Thin ALT Flap: A Comprehensive Evaluation of Perfusion-Related Complications and Donor Morbidity

Background: With an increasing need for thin flap, the use of super-thin anterolateral thigh (ALT) flaps, raised above the supra-superficial fascia, has drawn great attention. Controversy remains regarding whether such thin flap elevation could affect postoperative outcomes, encompassing perfusion-related complications (PRC) and donor morbidities. This study aimed to evaluate the outcomes of super-thin ALT flap-based reconstruction compared with those of suprafascially elevated flaps. Method: Patients who underwent free ALT flap-based reconstruction between March 2017 and June 2023 were reviewed, and categorized into two groups based on flap elevation plane; super-thin, and suprafascial. Development of PRC and donor morbidities including paresthesia, were compared. Independent associations of the elevation plane with complication profiles were evaluated. Further analyses were conducted using propensity-score matching. Results: In total, 208 cases were analyzed: 80 super-thin and 128 suprafascial ALT flaps. Nineteen cases (9.1%) experienced PRC, including four total and 14 partial necrosis. The incidence of overall and each type of PRC did not differ based on flap elevation plane even after adjusting for other variables. The super-thin group exhibited significantly lower donor complications compared to the others, upheld in multivariable analyses. Elevating the flaps with a super-thin fashion allowed for a higher rate of preservation of the lateral femoral cutaneous nerve, resulting in a significantly lower rate of postoperative paresthesia. Similar associations were observed in the propensity-score matching analysis. Conclusions: Super-thin ALT flap elevation might not appear to increase PRC risk, while reduces donor complications, compared to suprafascial elevation.