Neutrophil-to-lymphocyte ratio and mesenteric ischemia: can it predict the etiology of mesenteric ischemic at computed tomography?

OBJECTIVES: To assess the usefulness of the neutrophil-to-lymphocyte ratio (NLR) as a predictive factor of acute mesenteric ischemia (AMI) in patients presenting at the emergency department (ED) with acute abdominal pain.
METHODS: This is a retrospective case-control study of patients older than 16 years admitted to the ED with acute abdominal pain with CT and histologic confirmation. The study group corresponded to patients with abdominal CT with radiological signs of AMI. The control group corresponded to patients with non-AMI findings in abdominal CT. Association measurements of NLR with radiological signs were compared with a paired-sample t test, and multivariate regression performed to analyze potential correlations. To assess the diagnosis capacity of NLR, ROC curves were calculated.
RESULTS: A total of 61 patients were included (32 cases and 29 controls). The cases of AMI showed higher mortality (43.8% vs 6.9%, p < 0.01) and higher NLR on the limit of statistical significance (13.8 vs 8.7, p = 0.053). Patients with AMI due to occlusion of the superior mesenteric artery (SMA) showed a higher NLR (8.3 vs 22.3, p < 0.001). The area under the curve (AUC) of the NLR for AMI due to occlusion of the SMA was 0.88 (95% CI 0.7-1.0, p = 0.001). No patient with NLR < 5 presented AMI due to occlusion of the SMA. An NLR of 12.8 showed a sensitivity of 92% and a specificity of 74% for AMI due to occlusion of SMA.
CONCLUSIONS: The NLR is a useful parameter of AMI of arterial origin due to occlusion of the SMA; it can help the clinician to raise suspicion of this diagnosis and the interpreting radiologist in the acquisition protocol for the CT study and would alert for an early surgical treatment.