During embolization of a large frontal arteriovenous malformation (AVM), Onyx-18 (eV3) was injected into an M3 branch of the middle cerebral artery via a Marathon microcatheter (eV3). After 40 minutes of embolization, the microcatheter could not be retracted due to fixation within the Onyx cast despite prolonged, robust attempts. A balloon microcatheter (Hyperform(TM), eV3) was advanced distally and inflated to provide distal counter tension, allowing microcatheter retrieval with minimal traction on the vasculature.