Neutrophil-to-lymphocyte ratio vs C-reactive protein as early predictors of anastomotic leakage after colorectal surgery: A retrospective cohort study

INTRODUCTION: Colorectal surgery (CRS) is associated with high morbidity rates, being anastomotic leakage (AL) one of the most serious complications with an incidence as high as 15%, accounting for up to a third of mortality in these procedures. The identification of pre-clinical markers may allow an early diagnosis and a timely intervention. The objective of the present study was to compare the performance of neutrophil-to-lymphocyte ratio (NLR) vs C-reactive protein (CRP) as early predictors of AL in CRS. METHODS: A retrospectively analyzed consecutive patients who underwent a colorectal surgery with anastomosis from June 2015 to April 2019. Receiver-operating characteristic (ROC) curves were used to find the cutoff points with the best diagnostic performance of AL. RESULTS: A total of 116 patients were included. From 43 patients (37%) who developed a total of 63 complications, 9 (7.76%) presented with an AL with a median of 8 days (range: 5–9). No significant differences were found for NLR between patients with vs without AL. In contrast, median CRP was significantly higher in patients who subsequently presented with AL, both on day 4 (164 vs 64, p = 0.04) and 5 (94 vs 44, p < 0.001) after surgery. The best predictive performance through ROC curves was found on postoperative day 5, with a CRP value of >54 mg/dL (AUC: 0.81, Sensitivity: 89%, Specificity: 61%). CONCLUSIONS: CRP appears superior to NLR as an early predictor of AL following CRS. The best diagnostic performance was obtained on postoperative day 5 with a cutoff value of >54 mg/dL.