[A case of dural arteriovenous fistula mimicking isolated transverse-sigmoid sinus successfully treated via the transvenous route].

A 66-year-old man was admitted to our hospital suffering from a left temporo-occipital intracerebral hematoma with bilateral thin subdural hematomas. Neurological examinations revealed slightly decreased cognitive function. Cerebral angiography demonstrated a left transverse-sigmoid dural arteriovenous fistula (TS-DAVF) with cortical venous reflux. The main feeders of the TS-DAVF consisted of multiple branches of the left occipital artery, and the left affected transverse-sigmoid sinus was occluded at both ends, i.e. the affected sinus was isolated. Transvenous embolization (TVE) was performed under general anesthesia. A contralateral approach failed to reach the affected sinus so that an ipsilateral approach was attempted. Contrast material was injected from the left jugular bulb and the route to the affected sinus was visualized. We succeeded in passing both a microguidewire and a microcatheter through the stenosed proximal sigmoid sinus to the fistula area of the affected sinus. The affected sinus was occluded with multiple platinum coils. Post-treatment angiography revealed disappearance of the cortical venous reflux and improvement of the cerebral perfusion. It is a challenging operation to approach an affected sinus through an occluded sinus. However, some cases of isolated TS-DAVFs have the possibility of being treated by TVE via the occluded sinus similarly to cavernous sinus DAVFs.