Middle Meningeal Artery Embolization in Chronic Subdural Hematoma in Post Shunted Normal Pressure Hydrocephalus

Shunted hydrocephalus patients are at an inherent risk of developing chronic subdural hematomas (cSDHs) from overdrainage. The preliminary results of three much-anticipated clinical trials (STEM, EMBOLISE, MAGIC-MT) have recently been presented, showing efficacy of middle meningeal artery embolization (MMA-E) in reducing observational failure and the need for reoperation in non-shunted patients, but the effect of this procedure in shunted patients remains to be further investigated. In this series, we present our institution's experience with MMA-E in shunted normal pressure hydrocephalus patients in comparison to standard of care (=SOC).

We compared nine patients with normal pressure hydrocephalus, ventriculoperitoneal shunt, and shunt-induced cSDHs receiving SOC, shunt adjustment with or without burr hole drainage, to seven patients receiving SOC with MMA-E. Hematoma size and age of patients were matched. Patients were followed with serial head computed tomography scans. Symptoms, hematoma size, time to resolution, resolution status, and embolization details were monitored.

Six of seven SDH patients receiving MMA-E resolved. One patient showed residual but stable 3 mm cSDH after reinitiation of hydrocephalus treatment. The median time to resolution was 139.5 and 89 days for SOC without and with surgery, and 309 or 88 days for SOC without and with surgery plus MMA-E. One MMA-E patient was lost to follow-up and presented more than one year later with decreasing SDH that resolved by post-MMA-E day 504.

MMA-E in shunt-induced cSDHs has not shown increased resolution speed compared to SOC and liberal use of MMA-E on this cohort may need to be further investigated.