Risk factors for postoperative intracranial infection after external ventricular drainage: a propensity score-matched...

To evaluate whether concurrent lumbar spinal drainage (LSD) increases the risk of postoperative intracranial infection in patients undergoing external ventricular drainage (EVD).

Consecutive adult EVD patients treated between 2014 and 2024 were enrolled in this retrospective study. The primary end point of this study was intracranial infection, while secondary endpoints included pulmonary infection, surgical site infection, urinary tract infection, bacteremia, shock, reoperation and length of ICU stay. We adopted 1:1 nearest-neighbor propensity score matching with a 0.2 caliper width to balance confounding variables between groups, followed by conditional logistic regression analysis. Sensitivity analyses were conducted using multivariable logistic regression, alternative propensity score matching with a 0.3 caliper width, and inverse probability of treatment weighting.

Among 891 screened patients, 888 met the inclusion criteria, comprising 268 patients in the combined EVD + LSD group and 620 patients in the EVD-only group. After 1:1 propensity score matching, 267 matched pairs were obtained. The incidence of intracranial infection was significantly higher in the LSD group than in the control group. Conditional logistic regression showed that concurrent LSD was independently associated with an increased risk of intracranial infection (OR 4.15, 95% CI 2.27-7.61, P<0.001), corroborated by all sensitivity analyses. Secondary outcomes revealed that the LSD group had significantly higher rates of pulmonary infection (86% vs 77%, OR 2.04, 95% CI 1.25-3.33, P=0.004), bacteremia (7.5% vs 1.5%, OR 5.00, 95% CI 1.71-14.63, P=0.003), and reoperation (28% vs 20%, OR 1.61, 95% CI 1.06-2.44, P=0.030), as well as a longer ICU stay (median difference 3 days, 95% CI 2-4, P<0.001).

In this study, concurrent LSD in patients with EVD was independently associated with an elevated risk of postoperative intracranial infection and multiple systemic complications. Our results suggest that tight adherence to appropriate clinical indications and enhanced infection surveillance may be beneficial in this group of patients.