Artificial emboli based on poly(2-hydroxyethyl methacrylate) particles in animal experiments

Spherical poly(2-hydroxyethyl methacrylate) particles 0.4-0.6 mm in diamete r prepared by suspension polymerization were used for embolization of the i nternal thoracic artery in ten dogs and the renal artery in two dogs. No si gns of toxic or irritating effect of poly(HEMA), either on the artery wall, or surrounding tissues were found in any animal in intervals of observatio n lasting two weeks, three months or one year. Possible neocapillarity, the presence of fibrous bundles among the particles of poly(HEMA) and, eventua lly, their slow degradation, were symptomatic of reparative processes.