Use of Middle Meningeal Artery Embolization for Treatment of Subdural Hematoma

History

A male patient in his 80s, with a prior medical history significant for only hypertension and cataracts, presented to his primary care provider for an annual wellness visit. During this visit, he complained of left-handed clumsiness. These events were characterized by transient sensory changes and difficulty performing fine motor tasks, such as shaving, holding utensils, and playing pickleball.

An MRI of his brain revealed a subacute on chronic right frontoparietal SDH with associated mass effect. I thought this was consistent with the likely etiology of his transient neurological symptoms, and he was referred to me for further management.

Presentation

The patient’s neurological examination was unremarkable, with intact cranial nerves, normal motor strength, and no sensory or coordination deficits. Functional assessment showed a Markwalder grade of 1, mRS of 1, and GCS of 15.

He denied headache, dizziness, new focal deficits, or other acute neurological symptoms, and he reported no recent trauma or anticoagulant use.

My assessment was that the patient’s episodic weakness and clumsiness with his left hand was likely associated with right-sided SDH.

Treatment

Given his diagnosis, we discussed his options, which included surgical evacuation of the hematoma, observation of the hematoma with serial imaging, or a relatively new procedure for the treatment of SDH called middle meningeal artery (MMA) embolization. Ultimately, I recommended he undergo MMA embolization, a minimally invasive endovascular technique as part of the now-completed EMBOLISE trial.

MMA embolization is a procedure in which a small catheter is navigated, from the wrist or the leg, into the MMA, which is a small artery that supplies the covering of the brain, and one that is felt to be potentially responsible for recurrence of SDHs. Once in the artery, it is intentionally occluded by injecting an embolysate.

The EMBOLISE trial was a multicenter prospective, randomized clinical study evaluating whether MMA embolization with Onyx, alone or as an adjunct to surgery, could reduce recurrence rates and the need for repeat interventions in patients with chronic or subacute SDHs.

The patient underwent endovascular treatment consisting of transarterial, transcatheter embolization of the right middle meningeal artery to address his subacute-on-chronic SDH. The procedure was performed through a small needle puncture in his radial artery, managed with temporary use of a transradial band and a bandage.

Outcome

He tolerated the procedure well without complication and was discharged home the same day. He continues to do very well. He denies any new or worsening neurological symptoms and has not experienced any further episodes of left-handed clumsiness. Surveillance imaging has shown resolution of his hematoma.

Analysis

MMA embolization has emerged for the treatment of subdural hematomas as a minimally invasive alternative for those hoping to avoid open surgery, or as an adjunct to surgery for those who do require surgical evacuation. There is now growing evidence, including the results from the EMBOLISE trial that were recently published in the New England Journal of Medicine, that the procedure can significantly reduce recurrence rates and the need for repeat operations.

The procedure, typically performed via a transradial or transfemoral approach with same-day or next-day discharge, targets the dural blood supply to the hematoma and is associated with less morbidity than open surgery. This approach is particularly valuable for older or medically fragile patients in whom traditional craniotomy carries higher risk, but it may be beneficial for anyone with a subacute or chronic subdural hematoma.

While most subdural hematomas occur associated with trauma, in elderly patients they may occur in a seemingly spontaneous fashion after minor, perhaps even trivial, blows to the head. As our population ages, the incidence of subdural hematomas will likely increase substantially. We believe that MMA embolization will be a useful way to manage many of these cases, limiting the number of patients who require major neurosurgical intervention.