Nomogram for predicting the risk of postoperative complications in free anterolateral thigh flap surgery

Free anterolateral thigh flap (ALT) surgery is critical for managing extremity soft tissue defects, but postoperative complications limit its broader application. This study aimed to develop a nomogram to predict the risk of postoperative complications following ALT surgery, improving postoperative management.

This retrospective cohort study included 909 patients who underwent ALT surgery from January 2016 to January 2024. Patients were divided into a development group (606) and a validation group (303). Multivariable logistic regression identified independent predictors of complications, which were incorporated into a nomogram. The predictive performance was evaluated using the concordance index (C-index) and receiver operating characteristic (ROC) curve analysis.

Independent risk factors for complications included vascular crisis, incomplete hemostasis, improper vascular anastomosis, flap length, flap length-to-width ratio, and prolonged surgery time. The nomogram demonstrated excellent predictive accuracy, with AUCs of 0.910 and 0.965 in the development and validation groups, respectively.

We developed a nomogram that accurately predicts the risk of postoperative complications in ALT flap surgery, helping clinicians assess patient risk and tailor treatment strategies.