SIR 2024
Embolization
Chen Guo, PhD
Research co-I of injectable embolic hydrogels
University of Minnesota
Financial relationships: Full list of relationships is listed on the CME information page.
Jafar Golzarian, MD
Professor
University of Minnesota / North Star Vascular
Financial relationships: Full list of relationships is listed on the CME information page.
To develop a biocompatible hydrogel that is deliverable through catheters, radiopaque, occlusive of arteries and selectively dissolvable.
Materials and Methods:
Injectable hydrogel composed of human hair keratin and poly(ethylene glycol) (PEG) was synthesized. In vitro characterizations including rheometry, injection forces, hemolysis and blood clotting time, and degradation and on-demand dissolution were performed. The feasibility of embolization and on-demand recanalization of arteries were evaluated in the renal arteries and hepatic arteries of three New Zealand white rabbits (male, ~ 4 kg). Histological assessment was performed on the kidneys and the liver.
Results:
IODD hydrogel with 20 wt% Visipaque demonstrated excellent mechanical properties and optimal injectability through both 4-F catheters and 2.8-F microcatheters. The IODD hydrogel can be dissolved on-demand within a couple of minutes using an aqueous dissolving agent. In acute rabbit models, the IODD hydrogel demonstrated good visibility under fluoroscope and durable occlusion of the renal and hepatic arteries. The selective recanalization of the vessels was shown in both renal and hepatic arteries where the microcatheter tip reached. Histology findings suggested the IODD hydrogel was predominantly distributed in the interlobular and arcuate arteries with very small amounts of hydrogel within rare glomeruli. The vessels were largely unaffected, although segments of renal artery and interlobular arteries had scattered individual cell necrosis and/or apoptosis of the tunica media smooth muscle cells, which may be improved with optimized dissolving agent dose.
Conclusion:
Visipaque containing IODD hydrogels were fabricated and demonstrated good mechanical properties and catheter injectability. Using rabbit acute models, the embolization and on-demand recanalization were successfully demonstrated in the renal and hepatic arteries. The conformable IODD hydrogels with the unique on-demand dissolution feature provides a platform technology for well controlled administration of embolic agents that can improve the clinical outcome and expand the use of embolotherapy.