. The tumor thrombi in the main portal vein were removed by the following procedures; (1) the circumferential incision of the first branch of the portal vein and removal of the exposed tumor thrombi with ring forceps and suction, (2) temporary clamping of the distal end, (3) dilatation of the round ligament and the venous cannula was inserted into the umbilical portion, (4) washing out of the residual tumor thrombi, (5) declamping of the distal end and closing suture of the cut end of the portal branch.