Prognostic Nutritional Index is a Predictor of Free Flap Failure in Extremity Reconstruction

The nutritional condition of patients is an important prognostic factor in various diseases. Free flap failure is a serious complication in patients undergoing free flap reconstruction, increasing morbidity and hospital costs. We evaluated the predictive factors, including the prognostic nutritional index (PNI), associated with free flap failure in extremity reconstruction. The PNI was calculated as follows: 10 × serum albumin (g/dL) + 0.005 × total lymphocyte count (per mm³), with a PNI <40 defined as low. Univariate and multivariate logistic regression analyses were performed to evaluate factors predictive of free flap failure. Postoperative outcomes, including duration of hospital stay and rate and duration of intensive care unit admission, were also evaluated. Of the 625 patients included, 38 (6.1%) experienced free flap failure. Multivariate logistic regression analysis revealed that predictors of free flap failure were female (odds ratio: 2.094; p = 0.031) and a low PNI (odds ratio: 3.859; p <0.001). The duration of hospital stay was significantly longer in patients who did than those who did not experience free flap failure (62.1 ± 55.5 days vs. 28.3 ± 24.4 days, p <0.001). A low PNI is associated with free flap failure, leading to prolonged hospital stay. This result suggests that the PNI can be simply and effectively used to predict free flap failure.