Distally Based Anterolateral Thigh Flap Algorithm for Unexpected Situations during Soft-Tissue Defect Reconstruction around the Knee

The distally based (d) anterolateral thigh (ALT) flap is an effective option for soft-tissue reconstruction around the knee; however, unexpected situations may occur intraoperatively, impeding flap harvest. The authors proposed an algorithm for surgical conversion for unexpected situations encountered intraoperatively. Between 2010 and 2021, 61 dALT flap harvests were attempted for soft-tissue defect reconstruction around the knee; 25 patients underwent surgical conversion for anomalies, including lack of a suitable perforator, hypoplasia of the descending branch, and compromised reverse flow from the descending branch. After excluding improper cases, 35 flaps were harvested as planned (group A) and 21 surgical conversion cases (group B) were finally enrolled for analysis. An algorithm was developed based on the cases in group B. Outcomes, including complication and flap loss rates, were compared between groups to verify the algorithm's rationality. In group B, the dALT flap was converted to a distally based anteromedial thigh flap ( n = 8), bipedicled dALT flap ( n = 4), distally based rectus femoris muscle flap ( n = 3), free ALT flap ( n = 2), or other locoregional flap that required additional incision ( n = 4). No differences in outcomes were observed between the two groups. The proposed contingency planning algorithm for dALT flap surgery proved rational, as surgical conversion could be made by means of the same incision in most cases, and outcomes generated by the algorithm were acceptable. Therapeutic, IV.