Matthew Da Silva, BMSc1, Ahmad Elnahas, MD, MSc, FRCSC2, Michelle C Cleghorn, MSc2, Timothy D Jackson, MD, MPH, FRCSC, FACS2, Allan Okrainec, MDCM, MHPE, FRCSC, FACS2, Fayez A Quereshy, MD, MBA, FRCSC2. 1University of Toronto, Faculty of Medicine, 2University Health Network, Division of General Surgery
Introduction: The neutrophil-to-lymphocyte ratio (NLR) is a marker that reflects systemic inflammation and organ dysfunction. Its use as a prognostic marker to predict complications following surgery has been recently described in the literature. The objective of our study was to evaluate the use of a high postoperative day one (POD1) NLR as a predictor for 30-day outcomes in patients undergoing bariatric surgery.
Methods and Procedures: We performed a retrospective chart review of 792 patients who underwent bariatric surgery at our institution between March 2012 and May 2014. Data was collected from medical charts, the National Surgical Quality Improvement Program and the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program databases. POD1 NLR values were obtained from complete blood counts along with a variety of 30-day clinical outcomes. Univariate and multivariate analyses were conducted to determine if POD1 NLR ≥ 10 could predict 30-day outcomes. This threshold was chosen because of its previously reported predictive value in gastrointestinal surgery.
Results: 699 Roux-en-Y gastric bypass surgeries (88%), and 93 sleeve gastrectomy surgeries (12%) were performed. All surgeries were performed laparoscopically. A total of 86 (10.9%) complications occurred in our study population, with 47 (5.9%) considered to be major. After covariate adjustment, POD1 NLR was found to be significantly associated with overall complications (OR 1.98, 95% CI: 1.01-3.87), major complications (OR 3.71, 95% CI: 1.76-7.82), reoperation (OR 3.63, 95% CI: 1.14-11.6), and a postoperative length of stay greater than 2 days (OR 3.7, 95% CI: 2.2-6.22). Although POD1 NLR was associated with readmission on univariate analysis, significance was not retained on multivariate analysis.
Conclusions: In our review of a large number of patients undergoing bariatric surgery, a POD1 NLR ≥ 10 was able to independently predict 30-day outcomes. This easily obtained inflammatory marker may help identify patients with a higher risk of developing early complications who may require longer hospital stay or reoperation. Further studies are needed to validate this threshold and explore its future clinical implications.