Nourishment of hepatocellular carcinoma cells through the portal blood flow with and without transcatheter arterial embolization.

BACKGROUND: Although transcatheter arterial embolization (TAE) for hepatocellular carcinoma (HCC) is very effective, local recurrence is not so rare. The reason is thought to be related to portal blood flow. The changes in the nourishing vessels in HCC after TAE were examined from the viewpoint of cell kinetics with direct reference to intracellular transportation of biochemical substrates, namely 5 bromo-2'-deoxyuridine (BrdU), an analogue of thymidine.
METHODS: To examine the cell kinetics of carcinoma cells, BrdU was infused intraoperatively in 23 patients with HCC (12 without TAE and 11 post-TAE patients) directly into the portal branch feeding the region to be resected. Specimens were prepared for immunohistochemical staining using BrdU monoclonal antibodies and analyzed using the labeling index (LI). The distribution of the labeled S-phase cell was also examined.
RESULTS: The LI in post-TAE patients was about six times higher than patients without TAE, with a significant difference at P < 0.001. Labeled cells were distributed not only peripherally but in the central part of the tumor, although the number was extremely small.
CONCLUSIONS: Some HCC cells, although small in number, are nourished by the portal blood flow directly throughout the viable tumor mass, which may act as the main blood supplier during the period after TAE. For greater local control of HCC, complete resection of HCC and/or the use of chemotherapy via not only the hepatic artery but also the portal blood flow are beneficial.