To assess the safety and efficacy of intraventricular nimodipine compared to oral nimodipine in patients with aneurysmal subarachnoid hemorrhage (aSAH).

Nimodipine, administered both orally and intravenously, is the only approved pharmacological treatment for improving the outcomes in aSAH. EG-1962 is a sustained-release formulation of nimodipine that is delivered directly into the ventricles via an external ventricular drain.

A comprehensive systematic search was conducted in PubMed, Cochrane, Scopus, and Web of Science databases on May 17, 2023. Eligible studies were screened and data were extracted from relevant articles. Pooled data were analyzed using risk ratios (RR) and 95% confidence intervals (CI) by the (meta) package in R-language.

Data from four clinical trials were pooled in a meta-analysis. When compared to oral nimodipine, intraventricular nimodipine showed a decrease in the risk of angiographic vasospasm (RR = 0.8, 95%CI [0.65-0.98], p = 0.03) but no difference in delayed cerebral ischemia (RR = 0.78, 95%CI [0.53-1.14]). However, in extended Glasgow Coma Scale (eGCS) scores categorized by World Federation of Neurological Society (WFNS) grades showed no significant differences were observed for grade 2 (RR = 0.96, 95%CI [0.6-1.55], p = 0.87), grade 3 (RR = 1.4, 95%CI [0.37-5.32], p = 0.62), grade 4 (RR = 0.79, 95%CI [0.49-1.27], p = 0.33), or grades 3 and 4 combined (RR = 1.14, 95%CI [0.6-2.15], p = 0.69). No significant differences were observed in hydrocephalus (RR = 1.2, 95%CI [0.81-1.81]), hypotension (RR = 0.69, 95%CI [0.14-3.38]), bacterial meningitis (RR = 1.39, 95%CI [0.32-6.10]), or serious adverse events, including death (RR = 0.90, 95%CI [0.71-1.13]).

Intraventricular nimodipine demonstrates a marginal risk reduction of angiographic vasospasm but not delayed cerebral ischemia compared with oral nimodipine in patients with aSAH. However, it does not confer additional benefits in terms of eGCS or other adverse events.