Traumatic middle meningeal arteriovenous fistula with acute epidural hematoma, a large venous pouch, and multiple shunt points: A case report

Background: Middle meningeal arteriovenous fistula (MMAVF) is a rare dural arteriovenous shunt that may occur after head trauma and can be associated with acute epidural hematoma (AEDH). Although spontaneous closure has been reported, treatment decisions may be challenging when a large shunted venous pouch is present despite the absence of cortical venous reflux (CVR). Case Description: A man in his 60s sustained a moderate traumatic brain injury after falling down the stairs. Initial computed tomography (CT) revealed right AEDH, right temporal bone fracture, left acute subdural hematoma, traumatic subarachnoid hemorrhage, and pneumocephalus. CT angiography (CTA) on postinjury day 6 suggested MMAVF at the fracture site. Digital subtraction angiography revealed multiple shunt points along the petrosquamous branch of the middle meningeal artery (MMA) with drainage predominantly into a large venous pouch. No CVR was observed. Given the large shunted venous pouch and concern for potential hemorrhagic risk, endovascular embolization was performed, resulting in occlusion of the dominant shunt point and near-complete obliteration of the shunt complex. Follow-up CTA showed no obvious enhancing vascular lesion suggestive of persistent shunting. Conclusion: In selected patients with head trauma, particularly those with AEDH and a fracture line crossing the MMA territory, CTA may be considered a minimally invasive screening tool for associated vascular lesions. Even without CVR, traumatic MMAVF with multiple shunt points and a large shunted venous pouch may warrant endovascular treatment based on angioarchitecture. The distinctive angioarchitecture observed in the present case may provide insight into the pathophysiology of traumatic MMAVF.