Pitfalls in endovascular treatment of dural arteriovenous fistulas involving the cavernous sinus

Angiographic changes of the sylvian veins, superior ophthalmic vein (SOV), and superior petrosal sinus (SPS) before and after endovascular treatment were determined for 18 patients with dural arteriovenous fistulas (AVFs) involving the cavernous sinus, and pitfalls of endovascular treatment, especially regarding venous drainage routes, for 3 of the patients were reported. Case 1: 57-year-old woman who presented with right abducens nerve palsy had a Barrow type D fistula in the right cavernous sinus draining into the bilateral inferior petrosal sinuses (IPS). One of the ipsilateral sylvian veins that had drained antegradely before treatment was occluded, and a small lacunar infarction in the corona radiata developed after transvenous embolization (TVE) of the right cavernous sinus. Case 2: 72-year-old woman who presented with symptoms of right ocular hypertension had a type D fistula in the right cavernous sinus draining into only the ipsilateral SOV. Conjunctival hyperemia persisted and was aggravated after angioanatomical obliteration of the fistula by transarterial embolization. Case 3: 55-year- old man who presented with left abducens nerve palsy had a type D fistula in the left cavernous sinus draining into the ipsilateral IPS and sylvian vein. The dural AVF was obliterated once with TVE, but recurred 1 week later with retrograde drainage into the ipsilateral SPS and mesencephalic veins. A second TVE resulted in complete obliteration of the fistula. In conclusion, detailed analysis of drainage routes is necessary for planning of treatment of patients with dural AVF, and prompt treatment is needed when redistribution of drainage route develops during or after TVE.