Bailout using NBCA for incomplete onyx embolization of tentorial dural arteriovenous fistula

Transarterial embolization using Onyx (Medtronic, Irvine, CA, USA) results in a high cure rate for complete obliteration of dural arteriovenous fistulas. However, incomplete obliteration occurs in some cases. Reports on the use of bailout therapy in such cases are limited. A 79-year-old man was diagnosed with Borden type III tentorial dural arteriovenous fistulas during a check-up for a headache. We first performed transarterial embolization with Onyx from a tentorial artery, but the fistula was not completely obliterated. We then performed an additional transarterial embolization with n-butyl-2-cyanoacrylate from the same artery in a single session, and the fistula was successfully bailed out, resulting in complete obliteration. Combining different liquid embolic materials, Onyx and n-butyl-2-cyanoacrylate, is an effective strategy for achieving complete obliteration in incomplete transarterial embolization treatment of dural arteriovenous fistulas.