Case report

A man in his early 20s was admitted with symptoms of vertigo, imbalance and vomiting. His relevant history included Ehlers-Danlos syndrome and aneurysms involving the bilateral internal carotid arteries and left vertebral artery. Computerized tomography angiography (CTA) imaging revealed a right internal carotid artery aneurysm which was treated by an interposition graft. The patient presented 6 months later with recurrent transient ischemic attacks in the right internal carotid distribution. CTA and Doppler ultrasound showed occlusion of the interposition graft. The patient returned to the operating room for surgical revision but the surgery resulted in failure to open the graft and subsequent stroke.

Two days after the attempt at surgical revision, the patient complained of diplopia, right ophthalmoplegia and a retro-orbital headache. Physical examination revealed a proptotic right eye with dilated conjectival vessels and a slight medial deviation at rest (figure 1A). Repeat CTA and angiography showed development of a right carotid cavernous fistula. The fistula was thought to be caused by placement of a Fogarty balloon into the cavernous segment of the internal carotid artery during the attempt at surgical revision and thrombectomy of the graft.

• Download figure
• Open in new tab
• Download powerpoint

Figure 1

(A) Photograph of patient's right eye showing a proptotic right eye with dilated conjectival vessels and a slight medial deviation at rest. (B) Lateral right common carotid angiogram showing occlusion of the right internal carotid artery 1 cm above the bifurcation to the level of the skull base. A direct carotid cavernous fistula is present. (C) Photograph showing level of puncture of the right internal carotid artery with the angiocatheter just anterior to the ear. A microcatheter is coaxially introduced through the angiocatheter. (D) Spot fluoroscopic image showing coil mass within the cavernous sinus and right internal carotid artery. (E) Lateral right common carotid angiogram after embolization, showing very minimal filling of the direct carotid cavernous fistula with slow flow within the inferior petrosal sinus and a cortical vein. (F) Follow-up magnetic resonance arteriogram at 2 months showing occlusion of the right direct carotid cavernous fistula.

Because of the patient's occluded right internal carotid artery and diagnosis of Ehlers-Danlos syndrome, treatment from a transarterial approach was thought to be dangerous since this would involve placing a microcatheter into the intracranial circulation and catheterizing the fistula through the anterior or posterior communicating arteries, putting the patient at risk of a dissection and possible stroke. An unsuccessful attempt at transvenous embolization from the right inferior petrosal vein, left inferior petrosal vein and right facial vein was performed. One month later the patient presented for a repeat attempt at closure of the fistula through a direct puncture of either the internal carotid artery or cavernous sinus.

The patient was intubated and placed under general anesthesia while in the supine position. The procedure was performed under neuromonitoring with somatosensory evoked potentials and EEG. Using ultrasound guidance, access was gained into the left common femoral artery and a 4 F sheath was placed. A right common carotid arteriogram demonstrated occlusion of the right internal carotid artery 1 cm above the carotid bifurcation to the skull base (figure 1B). The native petrous segment of the right internal carotid artery filled from collaterals off the ascending pharyngeal artery. A high-flow direct carotid cavernous fistula was identified draining anterior through the right superior and inferior ophthalmic veins and posterior through the right inferior petrosal, right superior petrosal and pterygoid venous plexus. Given our limited experience with direct transorbital puncture of the cavernous sinus and the venous engorgement of the eye, we decided to performed direct puncture of the internal carotid artery at the level of the skull base.

Under ultrasound and fluoroscopic guidance, an 18 G angiocatheter was angled cephalad into the highest cervical segment of the right internal carotid artery (figure 1C). An SL-10 microcatheter (Stryker Neurovascular, Fremont, California, USA) was introduced through the angiocatheter and advanced over a Synchro-14 wire (Stryker Neurovascular) into the right cavernous sinus. The cavernous sinus and right internal carotid artery was then successfully filled with a combination of Microplex/Cosmos coils and HydroSoft Helical coils (Microvention Inc, Tustin, California, USA) (figure 1D). Angiograms of the right common carotid artery, left common carotid artery and left vertebral artery demonstrated minimal filling of the direct carotid cavernous fistula (figure 1E) with very slow flow within the right inferior petrosal sinus and a cortical vein.

Follow-up clinic visit and magnetic resonance arteriography 2 months after the procedure demonstrated closure of the fistula with resolution of the proptotic right eye, opthalmoplegia and dilated conjectival vessels (figure 1F).