Embolisation of high flow extracranial/peripheral arteriovenous malformations (AVMs) with ethylene vinyl alcohol copolymer (ONYX®) in children—Birmingham Children’s Hospital experience

ONYX® is a non-adhesive liquid embolic agent, ethylene vinyl alcohol copolymer dissolved in various concentration of dimethyl sulfoxide. Onyx has been used for endovascular treatment of cerebral vascular malformation. In our series, we present our experience in seven paediatric patients with peripheral high-flow arteriovenous malformations (AVMs) treated with Onyx. Seven patients were treated in our institution from 2005 to 2010 for their AV malformation with Onyx embolisation. Their case notes were reviewed and data on site, stage, number of embolisations, pre and post-procedure stage of AVMs and complications noted. AVMs involving profunda femoris, posterior tibial arteries, facial and maxillary arteries were embolised with Onyx. Three patients received multiple embolisation procedures. All AVMs were downgraded from Schobinger III to Schobinger I after embolisation. Two patients underwent surgical removal of AVM post-embolisation. One patient experienced post-procedure pain, skin ulceration and necrosis, which was managed conservatively. One patient had stiffness and discomfort over ankle joint. Onyx induced an inflammatory reaction in tissues in one patient. In our experience, Onyx embolisation of extracranial high-flow AVM in children has shown to downgrade the stage of AVMs which are otherwise very difficult condition to treat surgically. Appropriate use of Onyx decreases complications and achieves symptomatic improvement. Level of Evidence: Level V, therapeutic study.