Middle Meningeal Artery Embolization for Chronic Subdural Hematoma: Meta-Analysis and Systematic Review

BACKGROUND: Chronic subdural hematoma is a very common neurosurgical condition. Although conventional surgical methods, such as burr hole irrigation, have been the mainstay of treatment, middle meningeal artery (MMA) embolization has emerged as a promising adjunctive or alternative treatment. The aim of this article was to present a meta-analysis and systematic review of this topic. METHODS: A literature search using keywords "chronic subdural hematoma," "chronic subdural hemorrhage," "refractory subdural hematoma," "refractory subdural hemorrhage," and "middle meningeal artery embolization" was conducted through October 2018. Outcome variables of hematoma recurrence, surgical complications, and modified Rankin Scale score were analyzed and compared between MMA embolization and conventional surgery cohorts. RESULTS: Three double-arm studies comparing embolization and conventional surgery groups and 6 single-arm case series were identified and analyzed. Hematoma recurrence rate was significantly lower in the embolization group compared with conventional treatment group (2.1% vs. 27.7%; odds ratio = 0.087; 95% confidence interval, 0.026-0.292; P < 0.001; I-2 = 0%); surgical complication rates were similar between groups (2.1% vs. 4.4%; odds ratio = 0.563; 95% confidence interval, 0.107-2.96; P = 0.497; I-2 = 27.5%). Number of patients with modified Rankin Scale score >2 in the embolization (12.5%) versus conventional treatment (9.1%) group showed no statistical difference (P = 0.689). A composite hematoma recurrence rate of 3.6% was found after summing the 6 case series. Composite recurrence and complication rates in the embolization cohorts of the double-arm studies and the case series were lower than literature values for conventional surgical treatments. CONCLUSIONS: MMA embolization is a promising treatment for chronic subdural hematoma. Future randomized clinical trials are needed.