Intermittent hepatic arterial or portal occlusion reduces liver tumor growth

The effect of repeated, intermittent hepatic vascular occlusion on liver tumor growth was studied in 32 rats. An adenocarcinoma was inoculated in the left liver lobe. After 8 days, the tumor size was measured and then, in three groups, the hepatic artery was occluded intermittently during 5 days for 15 min, 1 hr, or 2 hr daily, respectively. The tumor growth after 6 days in these groups was compared with that in a group where instead the portal vein was occluded intermittently during 5 days for 15 min, and with that in a group of sham-operated control rats. In the control rats, the tumor volume (mean +/- SEM) increased from 0.16 +/- 0.03 to 1.34 +/- 0.15 cm3 during the 6 days of experiment. It was found that repeated, intermittent occlusion of the hepatic artery or the portal vein, retarded the liver tumor growth to 30-60% of the growth rate in sham-operated controls (P less than or equal to 0.015). The 15-min daily hepatic artery or portal vein occlusion was found to reduce the tumor growth rate as much as daily hepatic artery occlusion for 2 hr. It is suggested that short, daily, intermittent hepatic vascular occlusions might be efficient in the palliative treatment of liver malignancy.