Evaluating the Predictive Value of Anthropometric Indices in DIEP Flap Reconstruction Outcomes

Background: Body Mass Index (BMI) has been commonly used to determine appropriateness for surgery. However, it fails to account for variations in lean mass and fat distribution, prompting the development of alternative anthropometric indices such as the Body Roundness Index (BRI), A Body Shape Index (ABSI), Body Adiposity Index (BAI), Conicity Index (CI), Abdominal Volume Index (AVI), Waist-Hip Ratio (WHR), and Waist-Height Ratio (WHtR). The present study evaluates which index best predicts adverse outcomes following deep inferior epigastric perforator (DIEP) flap surgery. Methods: A retrospective review was conducted on DIEP flap patients between 2017 and 2023. Patient demographics and postoperative complications were documented, and anthropometric indices were calculated using preoperative imaging measurements. Univariate and multivariate analyses were performed to assess the associations between these indices and surgical outcomes, with statistical significance set at p < 0.05. Results: Among 384 patients studied, 84 experienced mild or more significant complications. Aside from a higher prevalence of diabetes in the complication cohort (p=0.01), baseline characteristics were comparable between the groups. Multivariable analysis identified BMI (p < 0.001), BRI (p = 0.01), AVI (p = 0.01) and WHtR (p = 0.02) as significant predictors of complications, 90-day readmissions, and longer hospital stays. AVI alone significantly predicted longer procedures (p=0.009). ABSI and Conicity Index did not significantly predict any outcomes. Conclusions: Among the indices, BRI and AVI demonstrated the strongest predictive power for complications, 90-day readmissions, and hospital length of stay following DIEP flap surgery, highlighting the importance of body composition in surgical outcomes and supporting their use alongside BMI for pre-operative risk assessment.