Inferior petroclival vein arteriovenous fistula mimicking cavernous sinus dural arteriovenous fistula: A case report.

Arteriovenous fistulas (AVFs) involving the inferior petroclival vein (IPCV) are extremely rare and may mimic cavernous sinus (CS) dural arteriovenous fistulas (DAVF) because of shared venous drainage patterns. A 72-year-old man presented with diplopia and left ocular chemosis. Carotid angiography revealed retrograde venous drainage into the superior ophthalmic vein via the inferior petrosal sinus (IPS) and CS. The initial findings suggested a CS-DAVF; however, three-dimensional angiography, including multiplanar reconstruction and maximum intensity projection analyses, identified shunt pouches in the IPCV and anterior condylar vein. Transvenous embolization via the IPS allowed the selective coil embolization of the IPCV shunt pouch while preserving the IPS. The IPCV-AVF resolved completely. Although the anterior condylar vein dural AVF remained, it was classified as Borden type I and was managed conservatively. The present case highlights the importance of detailed three-dimensional angiographic analysis to distinguish IPCV-AVF from CS-DAVF and guide effective treatment.