Transvenous Onyx Embolization of a Type D Carotid-Cavernous-Fistula: Operative Video

Carotid-cavernous fistulas (CCFs) are acquired pathologic shunts between the carotid circulation and the cavernous sinus that result in venous congestion.¹ They often present with ocular symptoms, such as chemosis, proptosis, and blurry vision. Cranial nerve deficits and increased intraocular pressure are often seen on the neuro-ophthalmologic examination.² If left untreated, they can lead to cortical venous reflux and intracranial hemorrhage. A cerebral angiogram is the gold standard to diagnose these lesions. The hallmark of dural CCF is opacification of venous structures in the arterial phase of the angiogram. Dependent on carotid branches contributing to the fistula, 4 types are classically defined by Barrow et al.³ When the fistula is indirect (types B-D), the goal of treatment is obliteration via the transvenous route.⁴ We present the case of a patient who had chemosis and proptosis of the left eye with imaging findings concerning for dural CCF (Video 1). An informed consent was obtained and the patient underwent a cerebral angiogram and treatment of the CCF. In the operative video, we showcase the treatment of a type D CCF using transvenous embolization with Onyx (Covidien, Irvine, CA) and achieve angiographic cure of the fistula. We were able to use Onyx for embolization since the superselective injection did not show cortical venous drainage. This is important as obliteration of cortical veins with liquid embolisate could cause venous infarcts. To our knowledge, this is the first video article that illustrates the endovascular embolization of a CCF and highlights the angiographic findings pre- and post-embolization.