Influence of Microcatheter Position and Distal Penetration on Outcomes After Middle Meningeal Artery Embolization for Chronic Subdural Hematoma with Liquid Embolics

Introduction: Middle meningeal artery embolization (MMAe) is being increasingly performed for the treatment of chronic subdural hematoma (cSDH) to decrease recurrence and enhance hematoma resolution. Optimal technical characteristics of the embolization have not been established.

Methods: A retrospective review of consecutive MMAe procedures with liquid embolics over a 3-year period was performed. Procedural variables included type of embolisate, microcatheter location, whether both anterior and posterior MMA branches were embolized, microcatheter position for embolization, distal penetration of embolisate in relation to the midline, and whether midline or contralateral penetration were achieved. Microcatheter position was trichotomized into proximal, intermediate, and distal based on branching patterns of anterior and posterior MMA convexity branches. Outcomes included need for rescue treatment, hematoma thickness reduction, and modified Rankin Scale (mRS) stabilization or improvement. Multivariate models were created for each outcome that included procedural variables and adjusted for age, hematoma thickness, midline shift, SDH acuity, hematoma characteristic, and surgery.

Results: A total of 102 embolizations on 84 patients (mean age 70.2 years) were included. Onyx was used in 83 embolizations (81.4%), n-BCA in 10 (9.8%), and Squid in 9 (8.8%). Rescue treatment was required in 8 (7.8%) patients. 81% of patients had hematoma thickness < 1cm at final follow-up (mean 8.8 months) and 66% had complete hematoma resolution. None of the procedural variables were associated with rescue treatment, mRS stabilization/improvement, reduction in hematoma thickness, or hematoma resolution at final follow-up.

Conclusion : Distal microcatheter position, midline/contralateral penetration of embolisate, and type of liquid embolic do not influence final hematoma resolution after MMAe. This requires further evaluation in large cohorts with core-lab adjudicated outcomes.