Clinical Analysis of 50 Cases of BAVM Embolization with Onyx, a Novel Liquid Embolic Agent

To report the embolization technique of using Onyx, a new liquid embolic agent, to treat cerebral arteriovenous malformations (AVMs) as well as its efficacy. 38 cases of cerebral AVMs located in eloquent area (motor, speech, visual nerve center), 9 in deep cerebral area, and another 3 cases in cerebellar hemisphere. The diameter of AVMs was smaller than 3cm in 10 cases, 3-6cm in 30 cases, and larger than 6cm in 10 cases.A 6F sheath was placed into the femoral artery after Selding's puncture. After a 6F guiding catheter was introduced into the internal carotid artery or vertebral artery, Ultraflow or Marathon microcatheter could be navigated into the nidus of AVMs.A long-slow injection of Onyx under fluoroscopic control was performed to embolize cerebral AVMs by adopting the "plug and push" technique. 10 AVM cases (20.0%) were considered to be totally occluded with Onyx in this group, 3 cases of which were found no regrowth by a 6-month follow-up. 25 cases (50%) were subtotally occluded while another 15 cases (30%) were partially embolized. Complications include: (1) severe cerebral hemorrhage occurred in three cases, two of them left hemiplegia after hematoma resection. (2) mild hemiplegia occurred in one lager frontal AVM patient. (3) mild visual deficit was left in one larger occipital AVM case. There was no severe complication in other 45 patients. Onyx has unique and distinctive superiority in treating cerebral AVMs. Nonetheless, the correct embolization technique should be learned to achieve good clinical results and to avoid complications. The long-term efficacy of Onyx embolization needs to be followed up.