Donor site in anterolateral thigh (ALT) free flaps: A systematic review of closure techniques and introduction of a management algorithm.

The anterolateral thigh (ALT) free flap is widely used in reconstructive microsurgery for its versatility and reliability, yet donor site management becomes challenging when flap dimensions exceed those for tension-free primary closure. The flap width-to-thigh circumference ratio (FW/TCR) is a potentially valuable objective decision-making tool. Given the heterogeneity of the reported closure techniques, this review aimed to map current techniques, identify gaps in evidence and propose a FW/TCR-based algorithm to standardise ALT donor site closure. A review of PubMed/MEDLINE, EMBASE, Cochrane Library and AMED databases was conducted from inception to October 2023, including English-language studies focused on ALT donor site closures. Data on closure techniques, outcomes, and complications were extracted. Overall, 27 studies met the inclusion criteria, describing direct primary closure, locoregional flaps, skin grafting, and adjunctive methods such as negative pressure wound therapy, acellular dermal matrices and tissue expansion. Direct primary closure was generally reported as feasible for FW/TCR < 16%. Once FW/TCR exceeded 30%, skin grafting or alternative solutions such as 'kiss' (split skin paddle) flaps were more frequently described. In the intermediate range (16-30%), locoregional flaps were commonly employed to avoid graft-related morbidity. Drawing on these findings, we propose a FW/TCR-based algorithm: (1) direct closure for FW/TCR < 16%, (2) locoregional flaps for FW/TCR 16-30%, and (3) grafting or alternative techniques if FW/TCR exceeds 30%. Standardising closure strategies using these thresholds may reduce donor site morbidity and optimise patient outcomes. Further high-level comparative studies are necessary to validate and refine these recommendations.