MMA Embolization With NeoCast for Subacute and Chronic Subdural Hematoma

Inclusion Criteria: * Participant whose age is ≥ 18 and ≤ 90 years; * Pre-morbid mRS ≤ 2; * Confirmed diagnosis of subacute or chronic subdural hematoma that measures ≥10 mm in greatest thickness; * Participant presents with one or more of the following corroborating neurological symptoms: headache; cognitive decline; speech difficulty; gait impairment or imbalance; focal neurological deficit; and/or seizure, within the last 30 days; * Participant is planned for middle meningeal artery embolization within ±7 days of surgical evacuation of hematoma via burr hole or craniotomy; * Participant or Legally Authorized Representative/Person Responsible for consenting on their behalf understands the nature of the procedure, consents to participation in the study and provides a signed informed consent form; * Participant (woman of child-bearing potential) with a current negative pregnancy test who has agreed to an appropriate method of contraception throughout the trial; * Participant is willing to return to the investigational site for follow-up visits. Exclusion Criteria: * Diagnosed with acute SDH * Participant with prior embolization of either MMA * Participant with urgent or emergent (within 1 hour of assessment) subdural hematoma evacuation needed * Participant with bilateral SDH where both sides require surgery or contralateral SDH \>5mm in greatest thickness * Participant identified with potentially dangerous anatomic variations leading to increased procedural risk, risk of …