Incidentally discovered dural arteriovenous fistula during middle meningeal artery embolization for the treatment of chronic subdural hematoma

BACKGROUND: The incidence of chronic subdural hematoma (CSDH) is increasing with population age and anticoagulant use. Embolization of the middle meningeal artery (MMA) is an emerging, less invasive alternative to open surgery in treating this condition. Dural arteriovenous fistula (DAVF) is a rare condition whose association with CSDH is not well understood. We present three cases with incidentally discovered DAVFs during MMA embolization for the treatment of CSDH that necessitated adjustments to initial treatment strategy. CASE DESCRIPTIONS: We retrospectively reviewed all MMA embolizations performed for the treatment of CSDH beginning in 9/2019 to 11/2020. Imaging and hospital course of three cases of incidentally discovered DAVF, including patient demographics, clinical presentation, methods of treatment, imaging and outcome were assessed. Thirty MMA embolizations were performed as primary or adjunct treatment of CSDH. DAVF was discovered angiographically in 3 (10%) cases. All patients reported a history of prior closed head injury, although the timing of injury and subdural blood product age did not correlate in 2 of the 3 cases. All subjects experienced complete symptomatic and radiographic resolution of the subdural hematoma and DAVF following intervention. CONCLUSION: As MMA embolization for CSDH becomes more frequent, so may the incidental diagnosis of DAVF. Awareness of this potential association is critical to diagnosing DAVF with angiography and altering treatment strategies as needed.