[PREOPERATIVE SIMULATION AND INTRAOPERATIVE NAVIGATION FOR LIVER SURGERY:THREE-DIMENSIONAL COMPUTED TOMOGRAPHY AND FLUORESCENCE IMAGING].

Recent developments in multidetector-row computed tomography (CT) provide precise information on liver anatomy. In the early 2000s, liver simulation based on three-dimensional (3D)-CT enabled estimation of total liver volume and liver volume flown from the portal vein or drained by the hepatic vein, facilitating liver resection planning. Additionally, 3D-CT simulation is useful for graft selection in living-donor liver transplantation. From April 2012, the simulation technique has been covered by the Japanese national health insurance system. Compared with the dissemination of liver simulation, liver surgery navigation is still in the developing stage. Recently, our group has clinically applied real-time virtual sonography, which synchronizes preoperative CT and supports tumor identification. The drawback of the system is the synchronization accuracy of both images. Another intraoperative navigation technique available is fluorescence imaging using indocyanine green (ICG) as a fluorescence source. ICG-fluorescence imaging enables the identification of liver malignancies, the bile duct, portal segment, and veno-occlusive regions in real time. However, deeply located (>10 mm) structures cannot be visualized because near-infrared light lacks tissue-penetration ability. Further technological advances are expected to improve liver surgery navigation and enhance the safety of liver surgery.