This study is designed to evaluate the effectiveness of endovascular embolization of middle meningeal artery following evacuation of subdural hematomas (SDHs) to assess rate of recurrence. The historical standard for treatment of subdural hematomas has been surgical evacuation through burr holes or craniotomies. Many of these patients are elderly patients who are high risk surgical candidates. A major concern is SDH recurrence.

Recurrences require frequent imaging, and will lead to increased length of hospital stay, increased morbidity,and re-operations. There are increasing number of reports that suggest that a less invasive approach such as endovascular embolization of the middle meningeal artery using standard endovascular materials and techniques may reduce the risk of recurrence. The reported outcomes in the current literature have been very positive when endovascular embolization has been used without surgery or as an adjuvant to surgery. However, there have been no studies directly comparing endovascular embolization following surgical evacuation to assess if this technique can actually reduce the complications of SDHs listed above. The investigators propose to study this treatment process by randomly assigning patients who have undergone surgical evacuation of SDHs into a control and treatment group. The control group will receive standard surgical evacuation of the hematoma. The study group will receive surgical evacuation followed by endovascular embolization.

The historical standard for treatment of chronic subdural hematomas (SDH) has been through surgical evacuation through burr holes or craniotomies. Many of these patients are elderly patients who are high risk surgical candidates. Unfortunately given the pathophysiology of SDHs there is a high rate of recurrence ranging 5-30% in the literature necessitation frequent imaging, increased length of hospital stay, increased morbidity, and increased rate of reoperations. A more novel and less invasive approach has been used to treat SDHs in this patient population. There are increasing reports of endovascular embolization of the middle meningeal artery using a less invasive endovascular approach for SDHs. The reported outcomes in literature have been very positive when endovascular embolization has been used without surgery or as an adjuvant to surgery. These reports include case series and retrospective reviews. There have been no studies directly comparing endovascular embolization following surgical evacuation to assess if this technique can actually benefit patients with chronic SDHs. The investigators propose to study this treatment process by randomly assigning patients who have undergone surgical evacuation of SDHs through burr holes into a control and treatment group. The control group (surgery) would only receive surgical evacuation of the hematoma using current standard of care. The treatment group (surgery plus) would receive surgical evacuation followed by endovascular embolization of the middle meningeal vessels using current standard of care. We will directly compare these two treatment modalities to obtain class I evidence on the efficacy of embolization for treatment of chronic subdural hematomas.

Inclusion Criteria:

• Patients 18-90 with chronic SDH
• Patients that require surgical evacuation of SDH following assessment by a neurosurgeon
• Glasgow Coma Scale (GCS) >6
• Modified Rankin Scale (mRs) <5

Exclusion Criteria:

• Patients < 18 or >90 years of age
• Pregnancy
• Patients with extensive multisystem trauma requiring multidisciplinary surgical interventions
• Chronic renal insufficiency with creatinine >1.8
• GCS <6
• mRs >4
• Genetic bleeding disorder
• Liver failure
• Coagulopathy
• Patients unable to consent who do not have an LAR available