Augmentation of Middle Meningeal Artery Embolization After Unilateral Subdural Hematoma Evacuation Using Contralateral Injection: Experience in 26 Consecutive Cases

Introduction: There are ongoing clinical studies assessing the effectiveness of middle meningeal artery (MMA) embolization versus surgical intervention for chronic subdural hematoma (cSDH) treatment. As the ipsilateral MMA circulation is often disrupted after surgery for cSDH evacuation, an over-the-top contralateral liquid embolic injection may enhance MMA tree occlusion of the symptomatic hemisphere for improved cSDH resolution and decreased rates of recurrence. Here, we report the radiographic follow-up of contralateral liquid embolic injections in 26 patients.

Methods: We reviewed a prospectively maintained database of the senior authors to identify cases of unilateral cSDH surgery with contralateral liquid embolic injection for MMA embolization.

Results: Over 37 months, 26 patients who underwent unilateral cSDH surgery with a contralateral liquid embolic injection were identified. Average age was 73±2 years (27-90 years), 14 (27%) were female. Prior unilateral surgeries include burr hole (n=13, 50%), craniotomy (n=12, 46%), and both (n=1, 4%). All cases underwent bilateral MMA embolization with a contralateral liquid embolic injection. Only anterior MMA branches were embolized in 3 cases (6%), posterior in 15% (n=8), and both branches (n=41, 79%). Contralateral injection resulted in penetration of the MMA tree of the surgical index side in 26 out 26 patients thereby augmenting embolization. Average follow-up was 100±19 days (1-704 days). cSDH was reduced by 5.6±0.1mm and the midline shift by 2.7±0.3mm at the most recent follow-up. Reduction of cSDH by > 50% was observed in 38% (n=10), with complete resolution in 4 (15%) patients. No cases required periprocedural rescue surgery and no vessel injuries or periprocedural complications were noted.

Conclusion : Embolization of the MMA vessels via a contralateral injection after an ipsilateral surgery provides additional embolization of the index surgical side. Further comparative studies are needed to investigate the cSDH recurrence outcomes in contralateral injection techniques.