Delayed effects in the treatment of carotid-cavernous fistulas

Carotid-cavernous fistulas may be classified into: (1) internal carotid, (2) external carotid, or (3) a combination of both. They may result from traumatic or spontaneous rupture of the carotid artery into the cavernous sinus. Intravascular embolization has become the treatment of choice for the management of carotid cavernous fistulas. The authors report the delayed effects after the treatment of carotid-cavernous fistulas with experience of 74 cases over the past 6 years. The delayed effects may be summarized as follows: (1) progressive spontaneous occlusion of the fistula after partial balloon embolization, (2) false aneurysms may decrease in size and be spontaneously sealed off, (3) transient and persistent third or sixth cranial nerve palsy may be seen in about 16% of 74 cases, (4) posttraumatic fibrosis with narrowing of the carotid artery may be apparent after total occlusion of the fistula, (5) a prematurely deflated balloon may be dislodged into the carotid artery or its branch, and (6) spontaneous obliteration of common channels from internal carotid artery may occur after total occlusion of external carotid channels in those cases with a combination of internal carotid- and external carotid-cavernous fistulas. Certainly the delayed effect will alter our future planning in the treatment of carotid cavernous fistulas.