Post on 14-Oct-2020
Onyx versus other liquid embolicagents for AVM treatment
LINC 2020, Leipzig, GermanyWalter A. Wohlgemuth
University Clinic and Policlinic of RadiologyMartin-Luther Universität Halle-Wittenberg, Germany
Conflicts of interest
Scientific grants:Siemens, Phillips, ab medica, ev3/covidien/medtronic, itm, Toshiba, Cook, W. L. Gore, Bracco
Lectures: ev3/covidien/medtronic, Biotronic, St Jude Medical, Abbott, Siemens, ab medica, Boston Scientific, itm Flowmedical, Terumo, W. L. Gore, IGEA
Consulting:1st WITiG, itm Flowmedical, Siemens, ev3/covidien/medtronic, ab medica
Embolisation agents
• Gelfoam• Embozene• DSM• PVA
Amplatzer VascularPlugsMicro Vascular Plugs
• Ethanol (-gel)• NBCA • EVOH
• Pushable Coils• Detachable Coils
ParticlesPlugs Liquid agentsCoils
Vessel diameter
Particles
Liquid embolic agents
Plugs
Microplugs
Coils
Microcoils
Embolic agents
Liquid embolic agents
Sclerosing Agents Glue Polymer EVOH
N-butyl-2-cyanoacrylate (n-BCA)
+
CAVE: Glued microcatheter → preflush glucose solution
Drawbacks• Flow and polymerisation time of N-butyl-2-cyanoacrylate are hard
to predict and sometimes quick– Passive distribution along the flow direction -> control?– Incomplete embolisation versus non-target embolisation
in veins / lung
• As close as possible to target– No active pushing of the agent
• Use requires experience and skills– Otherwise microcatheter gets stuck (detachable-tip microcatheter
may be a solution)
• „Inject and pull“ approach– Recanulation of vessel necessary
α-hexyl-cyanoacrylate (Magic glue)
• Slower polymerisation speed
• More “elastic” cast
• Less adhesive to microcatheter
• Remains liquid until it comes in contact with tissue
Chain of 6 carbons -> hexyl
α-hexyl-cyanoacrylate (Magic glue)
Only pre Clinical Study:
• This new glue has the same occlusive efficacy in short and long term than n-butyl-2-cyanoacrylate
• Adhesion strength of hexyl-cyanoacrylate to catheterwas less important than that of n-butyl-2-cyanoacrylate
• CE mark in 2018
Preclinical study on an animal model of a new non-adhesive cyanoacrylate (Purefill®) for arterial embolization - J. Izaaryene & al - Diagnostic and Interventional Imaging (2016) 97, 1109 – 1116 - http://dx.doi.org/10.1016/j.diii.2016.05.013
Indications for cyanoacrylates
• Acute bleeding
• Preoperative tumor embolisation
• Neuroradiology: spinal AVM, (cer AVM)
• Portal vein embolisation
• Thoracic duct embolisation
• Various other indications
Ethylene Vinyl Alcohol Copolymer (EVOH)
• Plastic: liquid monomer → solid polymer – Onyx (18, 34)L, Squid (12,18,34)L, (PHIL)
• Slow polymerisation (diffusion of solvent DMSO)– Controlled process, central core remains liquid
– Longer procedure time, higher radiation dose
• Used material has to be DMSO compatible
• Radioopaque (micronized Tantalum / Iodine)
• Expansive
• Very controllable + effective, but…– Local complications: pain, ischemia, necrosis
– Systemic complications: Upper dose of DMSO 0.583 ml/kg bodyweight
EVOH: Unique properties
• Active distribution even against blood stream possible
– As opposed to passive, flow-related distribution(NBCA, alcohol)
– Retrograde injection: from transvenous to arterial
• „plug & push technique“
• CM-injection in DSA is flow-passive as well……
– DSA-images of AVM may not display the complete angio-anatomy, flow changes during embolisation
– AVM nidus is larger than visualised in DSA
Indications for EVOH
• Neuroradiology: AVM, V. Galen aneurysm, dAVF
• Acute bleeding
• Endoleak embolization after EVAR (type II, type I)
• Arteriovenous malformations (body)
• (Preoperative tumor embolisation)
• (bile leakage)
• Various other indications
Univ.-Prof. Dr. Dr. Walter A. WohlgemuthUniversity Clinic and Policlinic of Radiology
Martin-Luther University Halle-Wittenberg, Germany
Thank you for your attention
Onyx versus other liquid embolicagents for AVM treatment
LINC 2020, Leipzig, GermanyWalter A. Wohlgemuth
University Clinic and Policlinic of RadiologyMartin-Luther Universität Halle-Wittenberg, Germany