Dartmouth Middle Meningeal Embolization Trial (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.

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