Selective transvenous embolization of dural arteriovenous fistulas involving the hypoglossal canal

The hypoglossal canal contains a venous plexus that connects the inferior petrous sinus, condylar vein, jugular vein and paravertebral plexus. The venous plexus is one of the venous drainage routes of the posterior skull base. Only a few cases of dural arteriovenous fistulas (AVTs) involving the hypoglossal canal have been reported. We describe three cases (a 62-year-old female, a 52-year-old male, and an 83-year-old male) of dural AVFs involving the hypoglossal canal. Symptoms were pulse-synchronous bruit in two cases and proptosislchemosis in one. All dural AVFs were mainly fed by the ipsilateral ascending pharyngeal artery. Two of three dural AVFs involving the hypoglossal canal mainly drained through the anterior condylar confluence into the inferior petrosal sinus retrogradely with antegrade drainage through the lateral condylar vein. The other one drained through the lateral and posterior condylar veins into the suboccipital cavernous sinus. All dural AVFs were completely occluded by selective transvenous embolization without any complications, and the symptoms disappeared within one week in all cases. Dural AVFs involving the hypoglossal canal can be successfully treated by selective transvenous embolization with critical evaluation of venous anatomy in each case.