Endovascular therapy for vasospasm secondary to subarachnoid hemorrhage: A meta-analysis and systematic review

Endovascular therapy has been used as an alternative treatment for vasospasm following subarachnoid hemorrhage. The effectiveness and safety of endovascular therapy are still controversial. We performed a systematic review and meta-analysis to identify any advantage of endovascular therapy over traditional medical treatment. We systematically reviewed related English publications by searching PubMed, Ovid, Cochrane library, and Web of Science up to May 2017.The risk ratios (RR) and 95% confidence intervals (CI) were synthesized with fixed effect model. Subgroup analyses and sensitivity analyses were conducted to check the robustness the result. Publication bias was measured with funnel plot. Eight cohort studies were included, receiving a mean score of 7 on the Newcastle-Ottawa Scale. The overall effect (RR 1.01, [95% CI 0.80-1.26]) found no significant difference in the outcome between the endovascular treatment and control groups but with heterogeneity (Chi²=18.07, p=0.01, I²=61%⁾. Subgroup analyses stratified by country, year of publication, treatment modality, follow-up time, and sensitivity analysis by excluding the most biased study yielded the same result (RR 1.19, [95% CI 0.94-1.52]), with rare heterogeneity (Chi²=4.21, p=0.65, I²=0⁾. Funnel plot was visually symmetric in sensitivity analysis. Despite good performance in reversing vasospasm in previous studies, endovascular therapy did not show superiority to traditional medical treatment in improving patient outcomes. Further randomized controlled studies are needed to elucidate this issue.