Posterior fossa dural arteriovenous fistula presenting clinically as a carotid-cavernous fistula treated by a direct access cavernous sinus approach

Dural arteriovenous fistulas (dAVFs) represent approximately 10-15% of all cerebral vascular malformations. Although dAVFs can occur anywhere in the brain, they occur most frequently in the cavernous and transverse-sigmoid sinuses. Posterior fossa dAVFs presenting clinically as carotid-cavernous fistulae (CCF) are rarely encountered in clinical practice. We discuss and illustrate an unusual case of a left posterior fossa dAVF that presented clinically with chemosis and early visual impairment, similar to that of CCF. This was subsequently treated by a direct access cavernous sinus approach. We describe the technique used to access the cavernous sinus directly in cases where conventional transvenous and transarterial routes have been exhausted.