Comparative Efficacy of Embolic Agents for Single-Session Meningeal Artery Embolization and Surgical Evacuation: Evaluating Liquids, Particles, and Adjunct Coils

BACKGROUND AND OBJECTIVES: Single-session middle meningeal artery embolization (MMAE) combined with surgical evacuation is an emerging strategy for management of patients with chronic subdural hematoma (cSDH). However, comparative outcome data based on embolic material selection in this setting remain limited. We compared clinical, radiographic, and functional outcomes of patients treated with cSDH using liquid or particle embolic agents and evaluated the effect of adjunctive coil use. METHODS: We conducted a retrospective multicenter cohort study of consecutive adults undergoing single-session MMAE with surgical evacuation for cSDH. Outcomes were compared by embolic material (liquid vs particle) using 1:1 propensity score matching. The impact of adjunctive coiling was assessed in the overall cohort. Associations were evaluated using multivariable logistic regression and reported as odds ratios with 95% CIs. RESULTS: Among 268 identified patients, 100 (50 liquid and 50 particle) were propensity-score matched for analysis. Rates of improved or stable functional status at last follow-up were similar between liquid (79.2%) and particle embolization (72.5%) groups (P = .701), as were ≥50% hematoma reduction (66.0% vs 72.0%, P = .464), postoperative complications (6.0% vs 8.0%, P = .672), and all-cause mortality (14.0% vs 14.0%, P = .951). Particle embolization was associated with a higher rate of needing any re-evacuation (20.0% vs 6.0%; adjusted odds ratio 5.13, 95% CI = 1.12-23.42, P = .035). Adjunct coiling lengthened procedure duration (203 [187-269] vs 198 [163-232] minutes, P = .019) without significant differences in clinical, radiographic, or adverse outcomes. CONCLUSION: In patients undergoing single-session MMAE with surgical evacuation for cSDH, liquid and particle embolic agents demonstrated comparable safety and functional and radiographic efficacy. However, liquid embolization was associated with significantly fewer reinterventions. Adjunctive coiling lengthened procedural time without differences in clinical or radiographic outcomes. Prospective comparative studies are needed to further define the role of embolic material and technical factors in patients undergoing evacuation and MMAE.