Preoperative Neutrophil-to-Lymphocyte Ratio as a Predictor of Morbidity and Mortality Following Open Thoracoabdominal...

To investigate the relationship between preoperative subclinical inflammation, quantified by the neutrophil-to-lymphocyte ratio (NLR), and postoperative outcomes following open thoracoabdominal aortic aneurysm repair (TAAAr).

This was a retrospective analysis from a single high-volume aortic center using the institutional aortic database. All patients who underwent TAAAr between 1997 and 2024 and had preoperative testing needed for NLR calculation were eligible. Maximally selected rank statistics were utilized to identify optimal NLR cutoff. Multivariable regression analysis, adjusted for key prognostic and surgical variables, was used to identify association. The primary outcome was cumulative mortality. The key secondary outcome was the composite incidence of in-hospital major adverse events (MAEs), including operative mortality (mortality prior to discharge), renal dysfunction, myocardial infarction, cerebrovascular accident, reintervention for hemorrhage, need for tracheostomy, and gastrointestinal complications.

A total of 591 patients were included. Operative mortality was low across the entire cohort (3.7% [22/591]). At median follow-up 84.0 ± 3.5 mo, the high-NLR (≥ 2.36) cohort (417/591) had higher cumulative mortality (40.3% [168/417] versus 25.9% [45/174], P = 0.001) compared to the low-NLR (<2.36) cohort. The high-NLR cohort also had increased incidence of MAEs (18.9% [79/417] versus 11.5% [20/174], P = 0.037). On multivariable analysis, NLR was independently associated with cumulative mortality (hazard ratio 1.05 95% confidence interval [1.01, 1.08], P = 0.01) and MAEs (odds ratio 1.07 95% confidence interval [1.01, 1.13], P = 0.027).

NLR was independently associated with cumulative mortality and MAEs after TAAAr. NLR may provide a novel metric for risk stratification in this high-risk patient cohort.