Neutrophil to lymphocyte ratio (NLR) of five predicts 30-day morbidity in ruptured abdominal aortic aneurysms (rAAA): A retrospective cohort study

• NLR >5 is a predictor of 30-day outcome in elective repair of AAA.
• NLR is a predictor of 2-year survival in a range of elective vascular interventions.
• The first study to examine the predictive role of NLR on rAAA outcome.
• NLR >5 is a predictor of 30-day morbidity in rAAA patients.
• NLR >5 was not a negative predictor of 30-day mortality.

BackgroundIn recent years the role of neutrophil to lymphocyte ratio (NLR) as an independent predictor of mortality and morbidity has gained significant attention in colorectal, upper gastrointestinal and cancer surgery. To date, no study has examined this in ruptured abdominal aortic aneurysms (rAAAs). This study aims to assess the role of NLR as a prognostic marker of 30-day (30d) morbidity and mortality in patients undergoing repair of rAAAs.MethodsData from 80 consecutive patients with a diagnosis of rAAAs from November 2007 to June 2014 were included. Receiver operating characteristic curve analysis was used to identify the optimal value for NLR in relation to 30d mortality and morbidity. Univariate and multivariate logistic regression analysis were used to determine the role of NLR after stratification by several clinical factors.Results25 patients (31.2%) had a low NLR (LNLR) and 55 patients (68.8%) had a high NLR (HNLR). Elevated NLR was significantly associated with low Hemoglobin and it was not associated with gender, age, AAA Size, history of HTN, COPD, smoking and renal failure. Patients with HNLR had higher 30d morbidity compared with the LNLR group (35 vs. 6 p = 0.001) but no difference in intraoperative blood loss, length of hospital, ITU stay and 30d mortality. High NLR through multivariate analysis was an independent prognostic factor for 30d morbidity [OR = 4.28, 95% (1.27–14.42), p = 0.02].ConclusionA preoperative NLR >5 is an independent predictive marker of 30d morbidity in rAAAs. This appears to be in line with earlier literature demonstrating similar outcome in the elective group of abdominal aortic aneurysm.