Safety and Additive Efficacy of Dual CSF Drainage (Ventricular + Lumbar) in Severe Aneurysmal Subarachnoid Hemorrhage: A Secondary Analysis of the EARLYDRAIN Trial

Background: The EARLYDRAIN trial demonstrated the efficacy of lumbar drainage (LD) in aneurysmal subarachnoid hemorrhage (aSAH) but did not differentiate between patients requiring dual drainage [LD plus external ventricular drainage (EVD)] versus single-catheter management. Objective: The purpose of this study was to investigate the safety and additive efficacy of simultaneous double drainage (EVD + LD) compared with isolated EVD in patients with high-grade aSAH, stratifying by actual device usage. Methods: This secondary analysis stratified 254 EARLYDRAIN trial participants on the basis of daily intensive care unit (ICU) device records. To minimize selection bias, the isolated LD cohort (n = 43), characterized by significantly milder admission severity (mean Glasgow Coma Scale (GCS) 13.3, p < 0.001), was excluded from efficacy models. The primary analysis compared simultaneous double drainage (n = 92) vs. isolated EVD (n = 119). Multivariable logistic regression models were adjusted for age, Hunt–Hess grade, modified Fisher grade, and total cerebrospinal fluid (CSF) drainage volume. Results: Double drainage and isolated EVD groups were well balanced for admission GCS (p = 0.672) and intraventricular hemorrhage prevalence (p = 0.355). Suspected infection rates were similar (47.8% vs. 44.5%, p = 0.631). In multivariable analysis, the drainage strategy (double vs. EVD) was not an independent predictor of clinical vasospasm (OR 1.02, p = 0.950), permanent shunt dependency (OR 0.75, p = 0.382), or unfavorable functional outcome (mRS 3–6) at 6 months (OR 0.75, p = 0.336). Instead, shunt dependency was independently predicted by higher total CSF drainage volume (p < 0.001) and age. Conversely, unfavorable functional outcome was driven exclusively by admission Hunt–Hess grade (p < 0.001) and age (p < 0.001), with total CSF volume showing no significance (p = 0.704). Conclusions: In patients with high-grade aSAH, the addition of a lumbar drain to an EVD is safe but does not independently mitigate vasospasm or improve functional outcomes when adjusted for injury severity. High-volume CSF drainage predicts shunt dependency but is not a marker of functional recovery, suggesting a “volume paradox” in severe hydrocephalus. Yet, because this was not a prespecified analysis, it is not possible to definitively establish the superiority of a dual-drainage strategy over ventricular drainage alone. Therefore, these results should be interpreted as exploratory.