Salem, Mohamed M.

BACKGROUND: Dural arteriovenous fistulas (dAVFs) located at craniocervical junction are extremely rare (1%-2% of intracranial/spinal dAVFs). Their angio-architectural complexity renders endovascular embolization to be challenging given multiple small feeders with risk of embolysate reflux into vertebral artery and limited transvenous access. The available literature discussing microsurgery for these lesions is limited to few case reports. OBJECTIVE: To report a multicenter experience assessing microsurgery safety/efficacy. METHODS: Prospectively maintained registries at 13 North American centers were queried to identify craniocervical junction dAVFs treated with microsurgery (2006-2021). RESULTS: Thirty-eight patients (median age 59.5 years, 44.7% female patients) were included. The most common presentation was subarachnoid/intracranial hemorrhage (47.4%) and myelopathy (36.8%) (92.1% of lesions Cognard type III-V). Direct meningeal branches from V3/4 vertebral artery segments supplied 84.2% of lesions. All lesions failed (n = 5, 13.2%) or were deemed inaccessible/unsafe to endovascular treatment. Far lateral craniotomy was the most used approach (94.7%). Intraoperative angiogram was performed in 39.5% of the cases, with angiographic cure in 94.7% of cases (median imaging follow-up of 9.2 months) and retreatment rate of 5.3%. Favorable last follow-up modified Rankin Scale of 0 to 2 was recorded in 81.6% of the patients with procedural complications of 2.6%. CONCLUSION: Craniocervical dAVFs represent rare entity of lesions presenting most commonly with hemorrhage or myelopathy because of venous congestion. Microsurgery using a far lateral approach provides robust exposure and visualization for these lesions and allows obliteration of the arterialized draining vein intradurally as close as possible to the fistula point. This approach was associated with a high rate of angiographic cure and favorable clinical outcomes.

Abstract A 40-yr-old male with no significant past medical history presented with sudden onset right-sided retro-orbital headache associated with vision loss after a session of strenuous exercise. Initial assessment with noncontrast head computed tomography at the local emergency department revealed a right sided occipital intracranial hemorrhage (ICH). On arrival the patient ad a left quadrantopsia with Glasgow Coma Scale of 15 and an ICH score of 0. A computed tomographic angiography showed a high density 6 × 9 mm vascular lesion associated with 2 tortuous vessels. Cerebral angiography revealed a right sided dural arteriovenous fistula, Cognard Type IV, with arterial feeders arising from dural branches of the right vertebral artery, the posterior division of the right middle meningeal artery and meningeal branches distal to the neuromeningeal trunk of the left ascending pharyngeal artery. 1 Four days after the ICH event the patient was treated with endovascular Onyx embolization of the fistula, through a transradial approach. Immediate angiographic assessment showed complete obliteration of the dAVF. The patient was discharged home and recovered his visual field deficit over 3 mo. The following operative video includes a discussion of the endovascular technique and treatment nuances associated with the transarterial management of a dural arteriovenous fistula. Patient consent was given prior to the procedure and consent and approval for this operative video was waived due to the retrospective nature of this manuscript and the anonymized video material.