Endovascular therapy of carotid cavernous fistulas.

The clinical manifestations of carotid cavernous fistulas, regardless of the type, depend on the pattern of venous drainage from the fistula. Venous drainage toward the orbit produces the usual syndrome of proptosis, chemosis, and arterialization of scleral veins. If the venous drainage is toward the brain, the signs and symptoms may not be as apparent, but the risk for catastrophic hemorrhage is much higher. Although many of these lesions may be managed in a conservative fashion, there are indications for urgent treatment to prevent a devastating hemorrhage or loss of vision. Direct carotid cavernous fistulas can usually be managed by transarterial embolization, most commonly with detachable balloons. The transvenous approach is most efficacious for treating indirect carotid cavernous fistulas.