A next-generation preoperative simulation and a new anatomical resection of the liver based on hybrid concept of portal perfusion and venous drainage / Шинэ санаа Шинэ нээлт

ABSTRACT

Background: Recent technical innovation enhances progresses in liver surgery. Now, for example, a preoperative 3D-simulation of the liver is indispensable for liver surgery. Detailed 3D-image revealed that portal perfusion area in cranial side of anterior segment sometimes surrounded superior right hepatic vein (SRHV). In such patients with HCC, SRHV should be resected for systematic resection. The aim of this presentation is to introduce various kinds of progresses in preoperative simulation and propose a new hepatectomy based on a hybrid concept of portal perfusion of anterior segment and hepatic venous drainage area of SRHV. A next generation simulation 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 and hepatic vasculature are simultaneously reconstructed in one dynamic MD-CT. This technique can avoid incorrect positional relationship when separately depicted DIC–CT or MRCP is fused on 3D-image by MD-CT, as well as unnecessary radiation exposure. Recently, we applied 3D-printer to a preoperative simulation of hepatic resection to better understand the 3D-anatomy 2) Assessment of partial functional reserve We have reported new methods to estimate 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. Fusion of both acialoscintigram of hepatic functional reserve and 3D-simulation by the above-mentioned software also well determines regional liver functional reserve. Those techniques provided accurate estimation of partial functional volume, and help surgeons’ decision making for resection volume of the liver. A new anatomical resection SRHV-involvement was observed in 17 out of 66 patients (26%). The large IRHV (more than 5 mm in diameter) was found in 16 out of 66 patients (24%). In patients with SRHV-involvement, the incidence of a large IRHV (8 of 17 48%) was significantly higher, compared to that in those without SRHV-involvement (8 of 49 16%). The procedures are as follows 1) encircling of anterior Glissonian pedicle, SRHV and inferior right hepatic vein (IRHV), 2) confirmation of demarcation line of anterior segment by occluding Glissonian pedicle and demarcation (congested) line by clamping proper hepatic artery and SRHV, and 3) IRHV-preserved complete resection of portal perfusion area plus drainage area of SRHV, combined with SRHV resection. Two patients having a large IRHV and HCC near the root of SRHV underwent a IRHV-preserved hepatectomy combined with SRHV resection (S8 + SRHVdrainage area in 1 and anterior segment + SRHV-drainage area in 1). Postoperative CT scan revealed complete resection of drainage area of SRHV and no congestion in the remnant posterior segment after hepatectomy due to excellent drainage through a large IR. Conclusions: Various advancements, such as preoperative 3D-simulation including partial functional reserve estimation and 3D-printer, enabled surgeons to perform hepatic resection easily and safely. In such HCC patients having a large IRHV, our new hepatectomy based on a hybrid concept of portal perfusion of anterior segment and venous drainage area of SRHV, combined with SRHV resection, is a promising option from the viewpoint of systematic resection (curability) and functional reserve of the future remnant liver in selected patients.