Arterial occlusion reduces tumour cell lodgement in the rat liver.

The lodgement of tumour cells (TCs) is a key event in the development of metastases in distant organs. Experimental and clinical studies have shown that ligation of the hepatic artery may reduce the mass of established metastases. In the present study the effect of hepatic artery or portal vein occlusion on the early phase of metastasis development, i.e. TC lodgement, was investigated. Occlusion of the hepatic artery immediately before intraportal TC infusion reduced TC lodgement, while a temporary occlusion of the portal vein directly after the TC infusion led to increased TC lodgement. It is speculated that the decrease in TC lodgement after arterial occlusion is due to local increase in blood flow, which might enhance the passage of the TCs through the liver, and to a decrease in pH causing an increased rate of TC destruction. The increased TC lodgement after portal vein occlusion, on the other hand, should mainly be due to flow reduction, promoting TC trapping in the liver microvasculature.