Difficult indirect carotid-cavernous fistulas--alternative techniques to gaining access for treatment

Carotid-cavernous fistulas (CCFs) are abnormal communications between the carotid arterial system and the cavernous sinus that occur mainly in elderly. Occasionally, treatment of indirect CCFs with conventional endovascular approach through large veins or the inferior petrosal sinus may not be possible. In these cases, a direct surgical cut down on to the superior ophthalmic vein (SOV) is necessary. We describe three such cases of embolization of CCFs through SOV, and their results. A retrospective case notes review of treated patients over the past 10 years in one tertiary center constituted our methodology. The fistulas in two cases were successfully coiled with complete obviation of symptoms and signs. The third case was complicated due to difficulty in canulating a deeply seated vein and so had to be abandoned and catheterized through contralateral superior petrosal sinus and treated with liquid embolic material Onyx(®) successfully. In cases where conventional access to the cavernous sinus may not be possible due to local variations of anatomy, multidisciplinary surgical approaches via the SOV provide an alternative route to successfully and safely close a CCF. However, unexpected anatomical variations could also be encountered within the SOV for which the surgeon should be prepared.