[Intrahepatic microvascular changes after intrahepatic arterial injection of lipiodol in normal and cirrhotic rats]

Iodized oil (Lipiodol) has been used for the diagnosis and treatment of hepatic malignancies, especially that of hepatocellular carcinoma. However, few reports have appeared concerning intrahepatic microvascular changes following intrahepatic arterial injection of Lipiodol. In the present study, Lipiodol was injected into the hepatic arteries of normal and cirrhotic rats, the changes of intrahepatic microvascular structures were serially investigated by scanning electron microscopy of microvasculature casts. In normal rats following intrahepatic arterial injection of Lipiodol, impairments of capillary vessels in the peribiliary plexus (PBP) were noted. The degrees of PBP impairments were most severe 2 days after the injection of Lipiodol. However, 10 days after the injection of Lipiodol, these impairments had almost completely vanished. There was no changes of terminal arterial and portal branches. In cirrhotic rats, proliferations of the perinodular arterial plexus (PNAP) and dilatations of the PBP were noted. After intrahepatic arterial injection of Lipiodol, the impairments of the PBP were noted, as in the normal rats. However, the degrees of these impairments were milder than those in the normal rats. It was considered that the decrease of the PBP impairments caused by Lipiodol were influenced by proliferation of the PNAP and dilatations of the PBP in cirrhotic rats. After intrahepatic arterial injection of Lipiodol in normal and cirrhotic rats, there was no development of collateral vessels. It was believed, therefore, that this fact was an advantage in the treatment of hepatic carcinoma by Lipiodol.