Timing and Type of Surgical Intervention for Chronic Subdural Hematoma in Patients Undergoing Middle Meningeal Artery Embolization

Introduction: Middle meningeal artery embolization (MMAe) is frequently performed as an adjunctive treatment for patients with chronic subdural hematoma (cSDH) undergoing hematoma evacuation. The optimal timing and type of surgery for patients undergoing MMAe has not been defined.

Methods: A retrospective review of consecutive MMAe procedures in patients with cSDH who also underwent hematoma evacuation over a 3-year period was performed. The outcomes were need for rescue treatment, hematoma thickness resolution, midline shift (MLS) resolution, and modified Rankin Scale (mRS) stabilization or improvement. Multivariate models were created for each outcome that included type and timing of surgery and adjusted for age, hematoma thickness, midline shift, SDH acuity, and hematoma characteristic.

Results: A total of 60 patients (mean age 69.1 years) who underwent 68 embolizations were included (8 patients had bilateral cSDH). Surgeries included burr holes (51.5%), subdural evacuating port system ([SEPS] 29.4%), and craniotomy (19.1%). Surgery was performed before MMAe in 76.5% of patients and after in 23.5%. Rescue treatment was required in 7 patients (10.3%). At a mean of 2.2 months follow-up the mean reduction in hematoma thickness was 68.9% and complete hematoma resolution occurred in 38.5% of patients. At final follow-up (mean 7 months) the mean reduction in hematoma thickness was 88.8% and 71.2% of patients had complete hematoma resolution. Timing of surgery was not associated with any of the outcomes. Compared to burr hole evacuation, SEPS was associated with lower odds of mRS stabilization or improvement (OR 0.03, 95% CI 0.001 – 0.30; p = 0.01) at a mean of 3.6 months post-op.

Conclusion : Timing of hematoma evacuation (before or after MMAe) does not influence need for rescue treatment, hematoma resolution, or mRS stabilization/improvement. However, SEPS is associated with lower odds of mRS stabilization/improvement than other surgical modalities. This requires validation in larger cohorts.