A 57-year-old man presented with jaundice. There was no past history of hepatitis or blood transfusion. Blood tests showed high levels of bilirubin, protein induced by vitamin K absence or antagonist-II (PIVKA-II) and carbohydrate antigen 19-9 (CA19-9). The indocyanine green retention test (ICGR15) could not be evaluated due to obstructive jaundice (Table 1a). Computed tomography (CT) scans showed a tumor 40 mm in diameter located in segment 6 with TT in the common hepatic bile duct (Fig. 1). Endoscopic retrograde cholangiography (ERCP) showed TT in the right hepatic duct and the common bile duct (Fig. 1). An endoscopic nasobiliary drainage (ENBD) tube was inserted in the left liver. ENBD was performed instead of percutaneous transhepatic biliary drainage (PTBD) due to the risk of tumor dissemination and bleeding, and insufficient dilation of the left intrahepatic bile duct. The level of total bilirubin in the bile (LTB) from the left liver as a future remnant liver was calculated at 1 week and 2 weeks after ENBD. LTB was calculated by multiplying bile density and volume obtained by ENBD. One week after ENBD, the total bilirubin density was 16.9 mg/dL and the bile volume was 205 ml. Two weeks after ENBD, the total bilirubin density was 46.0 mg/dL and the bile volume was 235 ml. The LTB from the left liver increased from 34.6 mg to 108.1 mg. However, bleeding from the TT and cholangitis occurred so thatneither the patient's general condition nor the serum level of bilirubin improved. One month after admission, the patient underwent thrombectomy in the bile duct, transection of the right hepatic bile duct and ligation of the right hepatic artery due to bleeding from the thrombus (Fig. 2). The bilirubin level immediately improved, and he was discharged from the hospital (Fig. 3). However, TT in the right portal vein developed (Fig. 4) and he was admitted to the hospital for a second operation. The serum level of total bilirubin was 1.3 mg/dl and ICGR15 was 34% at the second admission. Although the volume of bile could not be measured, the total bilirubin density in the bile from the left liver by ERCP was 40 mg/dL (Table 1b). 99mT-galactosyl human serum albumin (99mTc-GSA) scintigraphy revealed a reduced accumulation of GSA in the right liver. In addition, left liver hypertrophy was observed on GSA scintigraphy (Fig. 4). We judged that right hepatectomy was possible because of the following reasons: (1) decrease in the serum level of total bilirubin, (2) hypertrophy of the left liver similar to portal vein embolization, (3) sufficient future remnant liver function on the basis of the total bilirubin density in the bile from the left liver. The patient underwent right hepatectomy for HCC. The total operation time was 326 min, and the total blood loss was 6264 g. The pathological findings yielded a diagnosis of moderately differentiated HCC with macroscopic portal vein and bile duct TT (Fig. 5). There was no intrahepatic metastasis, and the surgical margin was negative. The patient's postoperative course was uneventful, and he was discharged on postoperative day 30 and he is well without recurrence 10 years after surgery.