Densitometric analysis of scans was performed to differentiate between a true increase in liver tissue of segments II/III and postoperative oedema. Using a transileocolic portal venous approach, a 5-Fr vascular sheath (Terumo, Leuven, Belgium) was placed via direct cannulation in the portal vein under general anaesthesia. The portal venous tree was imaged using a 5-Fr angiographic cobra catheter (Terumo) in the main portal vein. Polyvinyl alcohol particles (Contour™; Boston Scientific, Cork, Ireland) and a histoacryl/lipiodol mixture (Braun, Tuttlingen, Germany and Guerbet, Roissy, France) were used to occlude portovenous branches to liver segments I and IV–VIII. Successful embolization was documented by repeat imaging. Initial preparation of the liver was performed as for extended right hepatectomy. check details After cholecystectomy, the hepatoduodenal ligament was dissected and a radical lymphadenectomy performed for oncological reasons and vascular identification. The right branches of the portal vein were identified, suture ligated and divided. Portal branches to segment I were routinely ligated and transected for anatomical reasons, and branches to segment IV were also ligated and divided, similar to interventional PVE. The right hepatic duct, the bile ducts to segments I and IV, and the corresponding arteries were preserved and marked with a vessel loop for easy transection during the subsequent procedure. Care was taken to preserve the branches of the left artery and bile duct. Complete mobilization of the right liver lobe, including ligation and transection of all right and left retrohepatic veins, was performed after hilar dissection. The isolated right and middle hepatic veins were marked with vessel loops, and transection of the liver parenchyma between segments II and III on one side, and I and IV–VIII on the other side, was performed with a cavitron ultrasonic surgical aspirator (CUSA®; Valleylab, Boulder, Colorado, USA). If the left bile duct had to be resected, a hepaticojejunostomy was performed to liver segments II and III during the initial operation. After completion of the ISLT procedure, liver segments I and IV–VIII (the extended right hepatectomy specimen), still arterialized, were wrapped in a soft plastic bag to avoid adhesions to the surrounding tissue before completion surgery. After sufficient liver volume increase had been confirmed by CT, removal of the isolated segments I and IV–VIII was scheduled. In this second operation the bag was removed and the remaining structures to the specimen were divided, that is the arteries, bile ducts and hepatic veins already isolated and tagged by vessel loops. Continuous data are presented as mean (s.d.). Statistical differences between groups were determined by one-way ANOVA for unbalanced design, followed by Student’s t test. P < 0·050 was considered statistically significant.