Introduction: Chronic subdural hematoma (CSDH) is associated with high recurrence rates. Middle meningeal artery embolization (MMAE) has emerged as a promising treatment option. In this systematic review and meta-analysis, we aimed to assess the safety and efficacy of MMAE for CSDH using liquid embolic agents and compare them with particles.
Methods: We systematically reviewed all studies describing MMAE for CSDH with liquid embolic agents, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Additionally, we included a cohort of patients from our institution using liquid and particle embolic agents. Data were analyzed using random-effects proportions and comparisons meta-analysis, and statistical heterogeneity was assessed.
Results: A total of 18 studies with 507 cases of MMAE with liquid embolic agents (including our institutional experience) were included in the analysis. The success rate was 99% (95% confidence interval [CI]: 98-100%), all complications rate was 1% (95% CI: 0-5%), major complications rate was 0% (95% CI: 0-0%), and mortality rate was 1% (95% CI: 0-6%). The rate of hematoma size reduction was 97% (95% CI: 73-100%), complete resolution 64% (95% CI: 33-87%), radiographic recurrence 3% (95% CI: 1-7%), and reoperation 3% (95% CI: 1-7%). No significant differences in outcomes were found between liquid and particle embolic agents. Sensitivity analyses revealed that liquid embolic agents were associated with lower reoperation rates in upfront MMAE (risk ratio 0.13, 95% CI: 0.02-0.95).
Conclusion: MMAE with liquid embolic agents is safe and effective for the treatment of CSDH. Outcomes are comparable to particles, but liquids were associated with a decreased risk of reoperation in upfront MMAE. However, further studies are needed to support our findings.
Keywords: Middle meningeal artery embolization; Onyx; Squid; chronic subdural hematoma; liquid embolic agents; nBCA.