Purpose: To report a rare complication that Onyx gel blocked the MCA trunk and branches unexpectedly during AVM embolism and our strategy to rescue. Material and methods: A 16 years old otherwise healthy girl hold a left side Spetzler - Martin grade III fronto-temporal AVM, during embolization, the L-MCA and its branches were blocked by Onyx completely, the patient was transferred to the operating room to extract the Onyx gel immediately. Result: After totally 10 arterotomies, all the Onyx gel were removed. 8 hours after occlusion, all arteries were then seen to pulsate. Conclusion: Iatrogenic MCA full-length acute occlusion is a rare and severe complication during AVM embolism. Carefully identify the feeding arteries, micro-catheter angiography before Onyx gel injection and balloon-assisted embolism could probably prevent it. Surgical operation to extract onyx gel and re-canalize MCA was recommended, AVM should be resect if possible.
Keywords: AVM; complication; embolism; onyx gel.