Association between preoperative neutrophil–lymphocyte ratio and mortality after plastic and reconstructive surgery

Predictive factors associated with postoperative mortality have not been extensively studied in plastic and reconstructive surgery. Neutrophil–lymphocyte ratio (NLR), a systemic inflammation index, has been shown to have a predictive value in surgery. We aimed to evaluate association between preoperative NLR and postoperative outcomes in patients undergoing plastic and reconstructive surgery. From January 2011 to July 2019, we identified 7089 consecutive adult patients undergoing plastic and reconstructive surgery. The patients were divided according to median value of preoperative NLR of 1.84. The low NLR group was composed of 3535 patients (49.9%), and 3554 patients (50.1%) were in the high NLR group. The primary outcome was mortality during the first year, and overall mortality and acute kidney injury were also compared. In further analysis, outcomes were compared according to quartile of NLR, and a receiver operating characteristic curve was constructed to estimate the threshold associated with 1-year mortality. This observational study showed that mortality during the first year after plastic and reconstructive surgery was significantly increased in the high NLR group (0.7% vs. 3.5%; hazard ratio, 4.23; 95% confidence interval, 2.69–6.63; p < 0.001), and a graded association was observed between preoperative NLR and 1-year mortality. The estimated threshold of preoperative NLR was 2.5, with an area under curve of 0.788. Preoperative NLR may be associated with 1-year mortality after plastic and reconstructive surgery. Further studies are needed to confirm our findings.