OnyxTM Liquid
Embolic System

The Onyx™ Liquid Embolic System is an ethylene vinyl alcohol (EVOH) copolymer dissolved in dimethyl sulfoxide (DMSO) for peripheral embolization.


The OnyxTM Liquid Embolic System (LES) is an ethylene vinyl alcohol (EVOH) copolymer that provides complete filling and distal penetration1 of peripheral lesions. Its non-adhesive properties permit more distal nidus embolization without significant risk of catheter entrapment, while higher viscosities allow for controlled deployment.2


OnyxTM 18 and 34 LES: Embolization of lesions in the peripheral vasculature, including arteriovenous malformations, and hypervascular tumors.

OnyxTM 34L LES: Embolization of lesions in the peripheral vasculature, including endoleaks, arteriovenous malformations, portal veins, bleeding, and tumors.

Product details

OnyxTM is a non-adhesive liquid embolic agent composed of EVOH dissolved in DMSO with suspended micronized tantalum powder. It is delivered through a microcatheter under fluoroscopic control.

Polymeric properties

  • Precipitation occurs on contact with aqueous solution (e.g., blood, water, contrast)
  • Flows like lava and solidifies from the outside in as solvent diffuses away
  • Delivers in a cohesive manner, forming a spongy, coherent embolus

Controlled delivery

  • Slow, controlled injection and delivery method
  • Ability to start and stop injections (pauses should not exceed two minutes)
  • Cohesive deposition and delivery
  • Excellent visibility3
  • Controlled angiography during embolic injection


OnyxTM 18 and 34 LES for peripheral use:

  • OnyxTM 18 LES (6% EVOH, viscosity of 18 cSt): travels more distally and penetrates deeper into the targeted lesion due to its lower viscosity compared to OnyxTM 34 (i.e., peripheral AVM nidus)
  • OnyxTM 34 LES (8% EVOH, viscosity of 34 cSt): has higher viscosity for more control in higher flow and large fistulous components

OnyxTM 34L LES for peripheral use:

  • 8% EVOH, viscosity of 34 cSt
  • Lower tantalum content than current version of OnyxTM 34 LES4
  • Less streak artifact on CT with good visibility during injection4

OnyxTM 34L LES packaging with 6 mL vial

  • 6 mL vial provides ease of use for large-volume treatments
  • Requires less storage space than four 1.5 mL vials of OnyxTM 34 LES
  • Environmentally friendly packaging made from 98% recyclable content

Hemorrhage case

Watch this case overview of a patient with lower gastrointestinal bleeding.

OnyxTM publication summaries

CT validation

OnyxTM 34L LES has less streak artifact on CT with good visibility during injection in comparison to OnyxTM 34 LES.4

OnyxTM 34L LES in 10 mm vessel

Onyx 34L liquid embolic system viewed in a computed tomography (CT) scan

OnyxTM 34 LES in 10 mm vessel

Onyx 34 liquid embolic system

Model specifications

OnyxTM Liquid Embolic System

Product code

Onyx formulation


Onyx 18 peripheral kit, 1.5 mL


Onyx 34 peripheral kit, 1.5 mL


Onyx 34L kit, 1.5 mL


Onyx 34L kit, 6 mL

OnyxTM LES accessories

Product code

Onyx LES accessory


Vortex-Genie®* 2 120 v/60 Hz with 1.5 mL vial attachment


Vortex-Genie 2 240 v/50 Hz with 1.5 mL
vial attachment


Mixer attachment for 6 mL and 1.5 mL


Syringe catheter interface adapter
(20 units/box)


1 mL luer-lock injector syringe
(10 units/box)

Manuals and technical guides

The technical manual includes indications, warnings, precautions, MRI information, and directions for use. Find it in the product labeling supplied with each device.

Additional resources


™Third-party brands are trademarks of their respective owners.

CT artifact validation in vitro using a water phantom tank to simulate body tissue and synthetic vessel. Document TR_NV 11300 RevA.

Images are property of Medtronic.



Urbano J, Manuel Cabrera J, Franco A, Alonso-Burgos A. Selective arterial embolization with ethylene-vinyl alcohol copolymer for control of massive lower gastrointestinal bleeding: feasibility and initial experience. J Vasc Interv Radiol. June 2014;25(6):839-846.


Yamada R, Uflacker A, Bourgeois A, Adams JD, Guimaraes M. Embolization Therapy: Principles and Clinical Applications. Philadelphia, PA: Wolters Kluwer; 2015:582.


Joseph S, Chadaga HC, Murali K. Endovascular Treatment of Cerebral AVM with Onyx - Initial Experience. Interv Neuroradiol. October 5, 2005;11(Suppl 1):171-178.


IFU 70721-001 Rev 01/13. 2 CT artifact validation in vitro using a water phantom tank to simulate body tissue and synthetic vessel. Document TR_NV 11300 Rev A 2013-08-20. All images property of Medtronic.