Liquid Embolic Volume Correlates With Improved Chronic Subdural Hematoma Resolution After Middle Meningeal Artery Embolization

BACKGROUND AND OBJECTIVE: The efficacy of middle meningeal artery (MMA) embolization for chronic subdural hematomas (cSDH) has been widely demonstrated in the literature. However, the role of distal embolic penetration on incidence of cSDH resolution remains controversial. In this study, we examined the effect of number of branches embolized and volume of embolic material used on the incidence of radiographic clearance of cSDH. METHODS: This is a retrospective review of all MMA embolizations performed at our institution for the treatment of cSDH. Baseline characteristics and technical parameters, including branches embolized and volume of embolic material used, were compared between patients with and without radiographic cSDH resolution at last follow-up. Further comparisons in outcomes were made between patients with multiple distal MMA branches embolized and those with a single branch embolized. Univariate statistical analysis was performed. RESULTS: A total of 131 MMA embolizations in 104 patients performed at our institution were included. Of the 131 cSDH, 70 (53.4%) showed complete radiographic resolution at last follow-up. Persistent cSDH was associated with older age ( P = .01), kidney disease ( P = .001), and larger subdural size ( P = .03). There was no difference in proportion of cSDH resolution between those with both anterior and posterior MMA branches embolized and those with a single branch embolized. However, the volume of embolic material used was significantly associated with subdural resolution ( P = .04). CONCLUSION: The volume of embolic material used during MMA embolization was significantly associated with radiographic cSDH resolution at last follow-up, while the number of MMA branches embolized did not affect cSDH resolution. Selection of MMA branches for better penetration of areas supplying the cSDH while minimizing the risk of reflux into nontarget branches can be considered in future optimization of this procedure.