Direct stick embolization of extremity arteriovenous malformations with ethylene vinyl alcohol copolymer.

Direct stick embolization (DSE) of high-flow peripheral arteriovenous malformations (AVMs) has previously been reported using n-butyl cyanoacrylate and ethanol. The use of ethylene vinyl alcohol copolymer (Onyx; Covidien, Plymouth, Minn) through this delivery route has been extremely limited, particularly in the peripheral interventional realm, owing to concerns about technique and conduit for delivery, skin discoloration, and ulceration. We describe three patients with relatively focal, symptomatic, congenital high-flow AVMs of the upper and lower extremity treated successfully by multifaceted approaches including transvenous coil embolization of the nidus venous outflow, transarterial embolization, and DSE of the AVM nidus with Onyx. Successful delivery of Onyx into the AVM nidus was achieved without nontarget embolization. Sustained symptomatic relief without recurrence or associated complications was achieved at 1 month, 3 months, and 6 months of follow-up. Nidus embolization is a key technical maneuver for optimal treatment of high-flow AVMs, although it is not always easily achievable by the transarterial route in more extensive, convoluted angioarchitectural varieties. With appropriate technical considerations and precautionary measures, Onyx can be safely and effectively delivered through DSE into the AVM nidus with satisfactory short-term and midterm clinical outcomes. This maneuver expands the armamentarium of the treating vascular surgeon facing complicated peripheral AVMs.