Rapid versus gradual weaning of external ventricular drains in aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis

INTRODUCTION: Aneurysmal subarachnoid hemorrhage commonly requires external ventricular drain (EVD) insertion. The effect of rapid versus gradual weaning on infection rates, hospital stay, and requirement for ventriculoperitoneal shunt (VPS) is not known. We aimed to compare rapid and gradual weaning strategies with measurable outcomes. EVIDENCE ACQUISITION: A PRISMA compliant systematic review and meta-analysis was conducted (PROSPERO ID 1144244). Articles published in MEDLINE, Embase, and Cochrane Library between inception and July 2025 were included. Weaning definitions, infection rates, hospital stay, and VPS insertion rates were identified. Binary and continuous outcomes were calculated using random effects meta-analysis models. EVIDENCE SYNTHESIS: In total, six studies (1802 patients) were included. The mean age of the included patients was 56.3 years, and 35% of the population were male. Clinical severity of aSAH was high: 54% presenting with WFNS IV-V and 37% with WFNS I-II. The most common definition of rapid weaning was immediate clamping (83.3%, N.=5/6). Rapid weaning was not associated with increased VPS requirement (RR=0.94, 95% CI 0.57-1.54, P=0.7547), or Infection rates (RR=0.99, 95% CI 0.55-1.76, P=0.9462). Rapid weaning was associated with reduced length of stay in hospital (five studies, 25.6 vs. 29.5 days, mean difference -4.3 [95% CI: -5.7, -3.0], P<0.001). CONCLUSIONS: Rapid weaning does not appear to be associated with reduced VPS dependence, or infection. Further studies are required to establish the ideal EVD weaning protocol to minimize infection, failure rates and hospital stay.