Do the tumor cells of hepatocellular carcinomas dislodge into the portal venous stream during hepatic resection?

The current study was undertaken to investigate whether or not tumor cells are dislodged into the portal venous stream during hepatic resection for hepatocellular carcinomas. A catheter was placed using echo guidance into the portal branch through the mesenteric vein in 31 patients. Cytologic examinations were done on multiple blood samples at various operative stages. Tumor cells were recovered in 7 of 31 patients in whom the tumor sizes were more than 5 cm and portal invasions were found microscopically and/or macroscopically. By contrast, the remaining 24 tumors were less than 5 cm in size and showed negative portal invasions. Recovery of the tumor cells was found, not during the earlier operative stage of mobilization or rotation of the hepatic lobe, but during the later stages of hilar dissection or hepatic parenchymal dissection. The portal pedicles should be divided before hepatic dissection in segmentectomy and lobectomy to lessen the chance of dissemination of intravasated tumor cells.