Dartmouth Middle Meningeal Embolization Trial (DaMMET) (DAMMET)

A Single Center Randomized Control Trial to Evaluate the Efficacy of Middle Meningeal Artery Embolization in the Treatment of Chronic Subdural Hematomas

Chronic subdural hematomas (cSDH) are one form of bleeding in the head. They are one of the most common diseases encountered by neurosurgeons across the country. The cSDH can push on the brain and produce symptoms that include seizures, weakness, loss of sensation, and confusion. Many of these cSDH produce repetitive bleeding. Treatment has largely consisted of surgical drainage of hematoma (also known as a blood clot) through either a small hole in the skull or open surgery. However, it is common for the cSDH to reappear despite these procedures. A recent study has shown a treatment failure rate of 27% and a need for additional surgery at 19%. A new approach to treatment of cSDH blocks the blood supply to the tissue that produces the repeated bleeding. Catheters are used to gain access to the middle meningeal artery (MMA), an artery that supplies the coverings of the brain. The artery is blocked using small particles or glue in a process called embolization. A recent pilot study of 72 patients who underwent MMA embolization showed a much lower rate of repeated bleeding. Based on these results, it is thought that this procedure holds promise in reducing the number of cSDH that require one or more operations. The goal of this study is to systematically examine if blocking the blood supply to the tissue responsible for repeated bleeding helps the cSDH resolve and improves patient outcomes.

Patients in this group will be offered all procedures and care deemed appropriate by the Neurosurgeon in charge of their care. This could include surgical intervention, observation, medical management.

Patients in this group will be treated with the standard of care treatment (the same care described in the arm "Symptomatic, standard of care") but will also undergo MMA embolization of the affected side(s).

Patients in this group will be offered all procedures deemed appropriate by the Neurosurgeon in charge of their care. This could include surgical intervention, observation, medical management.

Patients in this group will be treated with the standard of care treatment (the same care described in the arm "Asymptomatic, standard of care") but will also undergo MMA embolization of the affected side(s).

Using established endovascular techniques and materials patient will have a diagnostic catheter based angiogram performed on the side(s) of the brain where the subdural hematoma is present. After verifying the vascular anatomy to ensure safety of the procedure the Middle Meningeal Artery will be embolized.

Standard of care could include observation or intervention including surgical drainage of subdural hematoma by bedside drain, Subdural Evacuating Port System (SEPS), burr hole or craniotomy

CT scan to evaluate for residual hematoma, comparing baseline to 6 months. Can be canceled if cSDH is completely resolved at 3 months

CT scan to evaluate for residual hematoma, comparing baseline to 12 months. Can be canceled if cSDH is completely resolved at 3 or 6 months

HPI and neurologic exam (standard clinic follow-up) to compare to presenting symptoms. This may be canceled if the symptoms and hematoma are completely resolved at 3 months

HPI and neurologic exam (standard clinic follow-up) to compare to presenting symptoms. This may be canceled if the symptoms and hematoma are completely resolved at 3 or 6 months

Comparison of NIHSS at admission to 6 month follow-up. May be canceled if cSDH resolved by 3 month follow up

Comparison of NIHSS at admission to 12 month follow-up. May be canceled if cSDH resolved by 3 or 6 month follow up

Inclusion Criteria: 18 years of age or older Have radiographic imaging showing a cSDH > 7mm in maximal thickness encompassing > 50% of the convexity (non-focal). Capable of giving consent for the procedure or have an acceptable surrogate capable of giving consent on the subject's behalf Exclusion Criteria: The cSDH is secondary to an underlying vascular malformation, tumor, cyst, spontaneous cerebrospinal fluid hypotension or previous craniotomy Life expectancy < 6 months Vascular anatomy that puts the patient at high risk for adverse events (e.g. critical carotid stenosis, abnormal external-internal carotid circulation) Incapable of being reasonably expected to be able to attend follow-up appointments at Dartmouth-Hitchcock Medical Center Vulnerable patients including homeless patients, incarcerated patients and mentally ill patients without appropriate medical decision-making proxy that the physician believes are incapable of appropriately assessing the risks of the procedure