Peripheral Vasculature Embolization with the Onyx Liquid Embolic System in a Swine Model

Area of Science:

• Interventional Radiology
• Vascular Surgery
• Biomaterials Science

Background:

• Peripheral embolization is a key interventional radiology technique.
• Ethylene Vinyl Alcohol (EVOH) copolymer is an embolic agent used in vascular interventions.
• Characterizing the histologic and inflammatory response to EVOH in peripheral embolization is crucial for understanding its safety and efficacy.

Purpose of the Study:

• To evaluate the histologic and inflammatory changes following peripheral embolization with Ethylene Vinyl Alcohol (EVOH).
• To assess the radiopacity of EVOH after a 1-minute mixing time.
• To determine the long-term outcomes of EVOH as a peripheral embolic agent in an animal model.

Main Methods:

• Peripheral embolization using EVOH (alone or with coils/plugs) was performed in Yucatan miniature pigs across various vessel sizes (<1 mm to 3-5 mm).
• Angiography was conducted at 1, 3, and 12 months to monitor embolic migration and vessel occlusion.
• Pathological evaluations assessed the biologic response, including tissue reaction, inflammation, and vessel trauma.

Main Results:

• EVOH exhibited sufficient radiopacity for procedural control in 98.2% of cases.
• Pathologic findings revealed minimal to mild inflammatory response and no significant tissue trauma or vessel injury.
• Complete to near-complete vessel occlusion was achieved, though 59.3% of treated vessels showed histologic evidence of recanalization over time.

Conclusions:

• EVOH is an effective peripheral embolic agent with adequate radiopacity and minimal adverse effects.
• The study supports acceptable long-term histologic outcomes for EVOH in peripheral embolization.
• EVOH demonstrates promise for peripheral vascular interventions in a swine model.