Background/Aims: To identify clinical significances of portal vein embolization (PVE) prior to major hepatectomy, we examined clinical parameters and outcome after right hepatectomy in patients who underwent PVE. Methodology: The subjects were 30 patients who underwent PVE (PVE group), and 52 patients (non-PVE), in whom PVE was considered unnecessary, followed by right hepatectomy for hepatobiliary cancer. Results: Total hepatic volume after PVE (1068±268 ml) tended to increase compared with before PVE (p=0.059). After PVE, the change in hemi-liver volume was 8.9±6.0%. Increases in hepatic volume of non-embolized left liver before and at 4 weeks after hepatectomy between the PVE and non-PVE groups were similar. Changes in hepatic volumes before and after PVE were not significantly influenced by background liver disease. After PVE, the functional liver volume (419±185cm 3) was significantly lower than morphological volume (564±165cm3) in the embolized liver (p<0.05). Although preoperative liver function was worse in the PVE group compared with non-PVE, serious hepatic complications were rarely observed in the PVE group. Conclusions: Marked changes in hepatic volume were noted after PVE in patients with impaired liver function and those who need large-volume right hepatectomy, especially in functional volume, suggesting that PVE is a useful procedure to prevent postoperative liver failure
