An animal model of occlusion-hyperthermia of the liver.

An animal model of partial hepatic artery occlusion and radiofrequency (RF)-induced hepatic hyperthermia was developed in the New Zealand white rabbit. Seventy-seven percent (10/13) of animals survived partial hepatic artery occlusion, 82% (41/50) survived RF-induced hepatic hyperthermia, and 66% (24/36) survived combined occlusion-hyperthermia. Mesenteric infarction secondary to inadvertent embolization of intestinal arteries was the principal cause of death in animals undergoing partial hepatic artery occlusion. Extrahepatic thermal toxicity appeared to be the major cause of death in animals subjected to hepatic hyperthermia or occlusion hyperthermia although some animals showed evidence of hepatic necrosis as well. Recent developments in our laboratory hold the promise that extrahepatic thermal toxicity can be eliminated by selectively focusing heat into the liver allowing exploration of the efficacy of occlusion-hyperthermia in controlling VX-2 tumors implanted in the rabbit liver.