Aneurysms of the intracavernous carotid artery: natural history and indications for treatment.

Of 37 patients with 44 intracavernous carotid artery aneurysms (ICCAAns) diagnosed between 1976 and 1988, patients with 20 aneurysms were followed without treatment for 5 months to 13 years (median, 2.4 years). Ten of the 20 ICCAAns were asymptomatic at diagnosis, and 10 were symptomatic. Three of the asymptomatic ICCAAns were symptomatic at follow-up. One of these required clipping because of a progressing cavernous sinus syndrome; the other 2 were minimally symptomatic and have not required treatment. Of the 10 initially symptomatic ICCAAns, 2 had not changed, 4 became more symptomatic, and 4 had symptomatically improved by follow-up. One patient with an ICCAAn that had not changed clinically was lost to follow-up 6 months after diagnosis. Of the 4 ICCAAns that became more symptomatic, 2 continue to be monitored, and 2 required intervention: one with detachable balloon occlusion of the aneurysm with preservation of the internal carotid artery lumen, and the other with gradual cervical internal carotid artery occlusion. The clinical course of this selected group of patients with ICCAAns suggests that the natural history of ICCAAns can be quite variable. Although clinical progression does occur, symptomatic ICCAAns also can improve spontaneously. Therapeutic intervention for asymptomatic ICCAAns should be reserved for patients with aneurysms arising at the anterior genu of the carotid siphon and/or extending into the subarachnoid space, where subarachnoid hemorrhage is most likely. Intervention for symptomatic ICCAAns should be reserved for patients with subarachnoid hemorrhage, epistaxis, severe facial or orbital pain, evidence of radiographic enlargement, progressive ophthalmoplegia, or progressive visual loss.