Hepatic dearterialization and permanent hepatic artery ligation can induce tumor necrosis but only of limited duration, partly due to a rapid development of arterial collaterals. The aim of this study was to determine if collateral formation could be reduced or prevented by repeated, transient dearterialization.Three groups of pigs were repeatedly and transiently dearterialized daily for 2 hours (n=5), 4 hours (n=5), and 6 hours (n=4), respectively, over a 4‐week‐period by means of a totally implantable vascular occluder described earlier by us. These pigs were compared with a group having permanent hepatic dearterialization (n=4). An additional group (n=3) served as a control and did not have dearterialization. After 4 weeks of treatment, hepatic angiograms were taken and absolute hepatic arterial blood flow was measured according to the reference sample method with radiolabeled microspheres. There were no demonstrable collaterals in the 2‐hour group, formation of some small collaterals in the 4‐hour group, and a fully developed collateral network in the 6‐hour group, with similar findings in the permanently dearterialized group. Absolute hepatic arterial blood flow was significantly lower in the 4‐hour group with obstructed hepatic artery compared to permanent hepatic dearterialization (p<0.01, Wilcoxon rank sum test) and highly significantly lower in the 2‐hour group (p<0.0001, Wilcoxon rank sum test).Thus, repeated and brief dearterialization seems to prevent the formation of arterial collaterals and makes repeated arterial ischemia of the liver possible which could be of value in the treatment of liver tumors. In addition, a patent artery makes continuous intra‐arterial cytostatic infusion possible.