Effects of cerebrospinal fluid drainage on patients with aneurysmal subarachnoid hemorrhage: an updated systematic review and meta-analysis.

OBJECTIVE: Cerebrospinal fluid drainage (CSFD) has been reported to be beneficial in patients with aneurysmal subarachnoid hemorrhage (aSAH), but there are controversial results among different studies. Moreover, the complications associated with CSFD have received widespread attention. In this study, an updated systematic review and meta-analysis were conducted with the aim of evaluating the relationships between CSFD and outcomes in aSAH patients. METHODS: A systematic search was carried out for eligible English publications up to 1 July 2025 in the PubMed, Embase, Cochrane Library, and Web of Science databases. The primary outcomes were a good prognosis and death, and the secondary outcomes included hydrocephalus, cerebral vasospasm (CVS), delayed cerebral ischemia (DCI), and intracranial infection (II). Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated by meta-analysis. RESULTS: A total of 3442 patients from 20 studies were included in the meta-analysis; 2258 patients received CSFD, and 1184 patients did not undergo drainage. Pooled analysis revealed that CSFD improved the prognosis (OR: 1.74; 95% CI: 1.15-2.61; P < 0.01) and reduced mortality (OR: 0.54; 95% CI: 0.38-0.76; P < 0.01). Meta-analysis of secondary outcomes suggested that patients who received CSFD had a lower incidence of CVS (OR: 0.52; 95% CI: 0.37-0.73; P < 0.01) and DCI (OR: 0.57; 95% CI: 0.40-0.81; P < 0.01) than those who did not receive drainage, but CSFD did not reduce the incidence of hydrocephalus. CSFD increased the risk of II (OR: 2.31; 95% CI: 1.24-4.29; P < 0.01). Subgroup analysis revealed that the results of different study methods and different drainage methods all showed that CSFD reduces the incidence of CVS but has no effect on the occurrence of hydrocephalus. However, for primary outcomes and other secondary outcomes, the results were inconsistent across subgroups. CONCLUSIONS: The current data show that CSFD tends to improve prognosis and reduce the incidence of cerebral vasospasm and delayed cerebral ischemia. However, it may increase the risk of II and has no effect on the occurrence of hydrocephalus. More well-designed randomized controlled trials are needed.