EXPERIMENTAL HEPATIC ARTERY EMBOLIZATION USING IVALON PARTICLES

Hepatic artery embolization (HAE) is an effective treatment for hepatic neoplasms. The human liver tolerated Gelfoam embolization; however, tumor devascularization was limited and inconsistent. Ivalon (polyvinyl alcohol foam) particles, 0.25 to 0.60 mm, were evaluated for improved devascularization.Twelve dogs were divided into two groups; 5 dogs (group A) had segmental hepatic embolization, and 7 dogs (group B) complete hepatic artery embolization. The liver function tests were checked before embolization and at 2 hours, 3 days, and 1,2,4, and 6 weeks after. Angiography pre- and postembolization and at 1 and 6 weeks monitored the degree of hepatic artery occlusion. In group B, 2 of the first 3 dogs died of pancreatic abscess. Prophylactic embolization of the gastroduodenal artery prior to HAE in the remaining 4 dogs prevented pancreatic abscess.In group A, all dogs had persistent segmental HA occlusion and their liver function tests were normal. In group B, there was elevation of alkaline phosphatase for 1 to 4 weeks in 3, SGOT between 3 days to 1 week in 2, and bilirubin in 1 dog. At sacrifice, the livers in group A were completely normal. In group B, the livers were normal in 4, but one had focal infarction and capsular fibrosis. Follow-up angiography showed partial recanalization and peripheral migration of Ivalon with persistent occlusion of small peripheral arteries. Intrahepatic collaterals i.e., intrasegmental and perivascular, were observed which was similar to those observed in human liver after Ivalon HAE.In summary, Ivalon particles reached smaller arteries and occluded more permanently than Gelfoam cubes in HAE. Segmental HAE was better tolerated than complete HAE.