The blood supply of colorectal liver metastases.

Post-mortem studies suggest that liver metastases obtain the majority of their nutrition from the hepatic artery; however, cytotoxic arterial perfusion with or without hepatic-artery ligation has not proved entirely successful as a therapeutic regime. In this study we have measured blood flow into colorectal liver metastases using xenon-133 (133Xe) clearance in patients undergoing surgery for colorectal cancer. Pre-operative measurements after direct parenchymal injection gave a mean flow of 41.5 +/- 22.5 ml/min/100 g which after hepatic arterial occlusion perfusion, was reduced to a mean of 5% of the pre-occlusion value. Dynamic blood-flow studies using the gamma camera were performed in the post-operative period by administration of 133Xe into both hepatic arterial and portal venous catheters. The initial distribution images indicated a predominant arterial perfusion to the metastases, but after hepatic-artery ligation, portal-vein perfusion to the metastases was statistically significantly increased. Hence, a compensatory haemodynamic mechanism exists which may account for the poor results of hepatic-artery ligation and perfusion alone.