Prognostic nomogram for predicting postoperative meningitis duration in skull base tumor surgery: a retrospective cohort study

OBJECTIVE: Postoperative meningitis (PM) is a severe complication following skull base tumor surgery, often resulting in prolonged hospitalization and increased morbidity. However, predicting the duration of PM remains challenging. This study aimed to identify prognostic factors influencing the duration of PM and to develop a predictive nomogram to guide individualized management and antibiotic therapy. METHODS: The authors conducted a retrospective cohort study of patients diagnosed with PM after skull base tumor surgery at a high-volume neurosurgical center between December 2018 and August 2024. Patients who received antibiotic treatment were included. Logistic regression analysis was performed to identify independent predictors of prolonged meningitis duration (> 7 and > 14 days). Based on these factors, predictive nomograms were developed and validated to estimate the probability of extended recovery times. RESULTS: Among 629 patients with PM, 240 (38%) experienced meningitis > 7 days and 69 (11%) had durations > 14 days. Multivariate analysis identified fever duration (> 38.5°C), highest CSF white blood cell (WBC) count, lowest CSF glucose level, highest blood WBC count, highest blood neutrophilic granulocyte proportion, repeat operation, and surgical approach as independent predictors of prolonged meningitis. The nomogram demonstrated good predictive performance, with concordance indices of 0.80 (95% CI 0.74-0.83) for the 7-day model and 0.79 (95% CI 0.70-0.85) for the 14-day model in the training cohort. Calibration curves and decision curve analyses further confirmed the accuracy and clinical utility of the models. CONCLUSIONS: The authors successfully developed and validated a prognostic nomogram to predict the duration of PM following skull base tumor surgery. This tool enables individualized risk stratification, informs the optimal duration of antibiotic therapy, and supports improved postoperative management. Prospective studies are warranted to further validate these findings across broader clinical settings.