Delayed Rupture of a Cavernous Carotid Aneurysm After Flow Diversion Resulting in Direct Carotid-Cavernous Fistula Treated With Transvenous Embolization: 2-Dimensional Operative Video

We present a 60- year- old female patient presenting with bilateral cavernous internal carotid artery aneurysms. She developed spontaneous thrombosis of the right cavernous aneurysm and right internal carotid artery. Three months later, she underwent treatment of the left cavernous aneurysm with flow diversion. She was discharged on postprocedure day 1, neurologically intact, and continued on dual antiplatelet medication. One month post-procedure, the patient presented to the emergency department with severe headache, new left eye ptosis, and inability to abduct the left eye. Computed tomography angiogram showed decreased filing of the aneurysm, and her symptoms were thought to be from cavernous sinus syndrome in the setting of aneurysmal thrombosis. She was started on a short course of steroids for cranial neuropathies. On postprocedure day 44, the patient was noted to have a severe headache, left eye ophthalmoplegia, proptosis, and chemosis with a computed tomography angiogram head evidencing a direct carotid-cavernous fistula (CCF). A transvenous CCF embolization was performed through the left inferior ophthalmic vein route. Complete resolution of the CCF as well as the cavernous aneurysm was achieved with coil embolization. The patient consented to the procedure and publication of her images and videos. CCF development after flow diversion of cavernous segment internal carotid artery aneurysms is uncommon occurring in 2.4%-11.4% of cases. (1,2) The cause has been attributed to aggressive thrombus- associated autolysis of the aneurysm. (3) Treatment options for CCF after initial treatment include transvenous embolization, ICA sacrifice, or flow diversion. (1,4,5) In the following video illustration, we narrate the highlights and nuances of this approach.