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

Abstract

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.

Keywords: Fistula; Posterior fossa; Technique; Vascular Malformation.

Figure 1

Digital subtraction angiography of (A) the left vertebral artery and (B) the ascending pharyngeal artery confirm the presence of a dural arteriovenous fistula in the left posterior fossa, draining anteriorly into the cavernous sinus and superior ophthalmic veins, contributing to the ophthalmic congestive symptoms.

Figure 2

The arrow denotes the access site of the 4 F sheath which was introduced into the left cavernous sinus through the floor of the left orbit.

Figure 3

Embolization of the fistulous point was performed with deposition of detachable platinum coils via a direct cavernous sinus approach. Post-embolization angiograms of (A) the left vertebral artery and (B) the ascending pharyngeal artery show complete occlusion of the left posterior fossa dural arteriovenous fistula.