Onyx (Ethylene-vinyl Alcohol Copolymer) in Peripheral Applications

Abstract

Onyx is a nonadhesive liquid embolic agent approved for the treatment of brain arteriovenous malformations. Here, the use of Onyx is discussed in different peripheral procedures. The Onyx's features, its manipulation, technical details, tips, and tricks are presented followed by illustrative cases.

Keywords: Onyx; embolization; peripheral procedures.

Figure 1

No more than 10–15 mm of Onyx is allowed to move backward along the tract (arrows) of the microcatheter (column formation around the microcatheter tip). The “plug” formation around the tip prevents further Onyx back-flow.

Figure 2

Right pelvic and proximal lower extremity angiogram demonstrates a complex arteriovenous malformation. An ultra-flow microcatheter was used for the distal selective Onyx (density 34) embolization, as close to the nidus as possible. Control angiogram shows complete exclusion of the lesion and preservation of the common, profunda, and superficial femoris arteries.

Figure 3

Patient with history of abdominal aorta aneurysm (AAA) stent graft repair. Twelve months follow-up computed tomography angiogram (CTA) shows endoleak type I-A. Microcatheter was inserted, through the suprarenal fixation portion of the stent graft, deep in the AAA sac. It was filled with Onyx using the “pull-back” and the “remodeling” techniques. Immediate control aortogram and 3 months CTA show no evidence of endoleak.

Figure 4

Patient with upper gastrointestinal bleeding refractory to transjugular intrahepatic portosystemic shunt (TIPS). Portal venogram shows extensive gastroesophageal collateral veins that were treated with Onyx embolization and the bleeding successfully controlled.

Figure 5

Patient with splenic laceration and intraperitoneal bleeding secondary to a motor vehicle accident (MVA). Selective splenic arteriogram shows the bleeding site, which was successfully controlled with superselective Onyx embolization.

Figure 6

Patient with history of MVA and right thigh pain. Right common femoral angiogram shows right profunda femoris branch pseudoaneurysm. Initially, microcoils were used to close the pseudoaneurysm outflow vessels and the lesion was treated with Onyx embolization using the “remodeling” technique.