Precision surgery for primary liver cancer.

Liver resection remains the best curative option for primary liver cancer, such as hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma. In particular, in liver resection for HCC, anatomical resection of the tumor-bearing segments is highly recommended to eradicate the intrahepatic metastases spreading through portal venous branches. Anatomical liver resection, including anatomical segmentectomy and subsegmentectomy using the dye-injection method, is technically demanding and requires experience for completion of a precise procedure. The recent development of imaging studies and new computer technologies has allowed for the preoperative design of the operative procedure, intraoperative navigation, and postoperative quality evaluation of the anatomical liver resection. Although these new technologies are related to the progress of artificial intelligence, the actual operative procedure is still performed as human-hand work. A precise anatomical liver resection still requires meticulous exposure of the boundary of hepatic venous tributaries with deep knowledge of liver anatomy and utilization of intraoperative ultrasonography.