Repeated arterial embolization of rat livers by degradable microspheres.

A transient arrest of arterial blood flow can be accomplished by intra-arterial injection of a new type of degradable microsphere. The effects of single and multiple injections of these microspheres into rat hepatic arteries were studied by measurements of fractional cardiac output distribution and 133Xe washout from the liver before and after embolization. Injection of these microspheres into the hepatic artery caused a significant but transient reduction of the arterial blood flow to the liver. Repetition of the injection several times over several days produced identical effects on each embolization. No signs of hepatic cell damage were detected after repeated embolization, as suggested by assay of the serum enzymes or the Bromsulphalein retention test.