INTRODUCTION: Recent technical innovation in liver surgery is remarkable. Now, for example, a preoperative 3D-simulation of the liver is a routine modality, and indispensable (or essential) for liver surgery. The aim of this presentation is to clarify various kinds of progresses and future perspective in liver surgery. PREOPERATIVE MODALITIES 1) One-stop shopping of 3D-simulation of the liver: We newly developed 3D-simulation using a software of SYNAPSE VINCENT Ver. 3.1 (Fujifilm Medical, Tokyo, Japan), in which biliary system is simultaneously reconstructed in one dynamic MD-CT. This technique avoids position error which occurred in 3D fusion image using another modality such as DIC–CT or MRCP, as well as unnecessary radiation exposure. 2) Assessment of partial functional reserve: We have reported new methods to astimate regional hepatic functional reserve using hepatocyte-phase of EOB-MRI (J Gastroenterol 2012), and fusion image of 3D-CT and asialoscintigraphy using 99m-Tc galactosyl human albumin. The method of EOB-MRI utilized character of hepatocyte-uptake of EOB through membrane transporters on hepatocytes. The other used fusion of both asialoscintigram of hepatic functional reserve and 3D-simulation by the above-mentioned software. Those techniques provided accurate estimation of partial functional volume, and help surgeons’ decision making of resection volume. INTRAOPERATIVE MODALITIES: 1) Navigation using iPad: navigation using iPad in which preoperative 3D-image data are uploaded in advance, tumor location, accurate and anatomical orientation can confirm in the operative field during operation. This technique enable not only operators also assistants or students to better understand precise anatomy. 2) Indocyanine green (ICG) fluorescent image-guided navigation: this technique using HyperEye Medical System (MIZUHO IKAKOGYO Co., Ltd. Tokyo, Japan) help us to confirm tattooing of target segment and parenchymal intersegmental plane, and detect hepatic tumors (metastatic and HCC) near liver surface as well as invisible tumor inside the liver. CONCLUSIONS: Various advancements such as preoperative 3D-simulation including partial functional reserve estimation and intraoperative navigation techniques enabled surgeons to easily and safely perform hepatic resection.

Background: The glissonean pedicle approach was introduced by Couinaud and Takasaki in the early 1980s. The key of the glissonean pedicle approach is clamping the pedicle first, secondly confirming the territory, and finally dissecting the liver parenchyma. In this presentation, we introduced our recent refinements of glissonean pedicle approach for liver resection. “Approach to the glissonean pedicles at the hepatic hilus” Couinaud described three approaches to the hepatic hilus. 1) Intra-fascial access (Control method): The conventional dissection at the hilus or within the sheath is referred to as intrafascial access However, dissection performed under the hilar plate is dangerous and surgeons have to consider any variations of the hepatic artery and bile ducts. 2) Extra-fascial access (Glissonean pedicle approach): The glissonean pedicle is dissected from the liver parenchyma at the hepatic hilus before dissecting the liver parenchyma. This procedure prevents intrahepatic metastasis of HCC, which spreads along the portal vein and improves the overall survival after surgery. 3) Extra-fascial and transfissural access: If the main portal fissure or the left suprahepatic fissure is opened after dissecting the liver parenchyma, the surgeon can confirm the pedicles that arise from the hilar plate or the umbilical plate. “Operative techniques” 1) Preoperative 3D simulation of the precise anatomy of portal vein, hepatic artery and bile duct at hepatic hilus should be performed. 2) Right glissonean pedicle: The hilar plate is detached from the quadrate lobe. The assistant pulls the liver parenchyma cranially and the operator conversely pulls the hepatoduodenal ligament caudally. Mayo scissors are inserted along the liver parenchyma between the liver parenchyma and glissonean capsule (Fig.1). Then forceps are inserted in the same way and the right main pedicle is taped (Fig.2). The right anterior and posterior glissonean pedicles are taped as well. 3) Left glissonean pedicle: The hilar plate is detached from the liver parenchyma. Then, the Arantius duct is confirmed and the left pedicle is dissected along the left pedicle at the ventral side of the Arantius duct. “Pitfall of glissonean pedicle approach” The right pedicle should be dissected in the liver side as much as possible to prevent the injury of left hepatic duct. If possible, the right pedicle is recommended to be dissected at the level of the second branches separately (Fig.3). The right posterior hepatic duct sometimes branches from the left hepatic duct and the Arantius duct is confirmed and the left pedicle should be dissected along the left pedicle at the ventral side of the Arantius duct because the right posterior hepatic duct branches from the left hepatic duct at the dorsal side of Arantius’ duct. In addition, the intraoperative cholangiogram should be used in the case with the abnormal anatomy of bile duct. Conclusions: Any anatomical hepatectomy can be performed using “glissonean pedicle approach” which allows simple, safe and easy liver resection.