TechniqueHepatoduodenal ligamentectomy (HL) is a challenging surgery for advanced perihilar cholangiocarcinoma extensively invading the hepatoduodenal ligament1-3. A liver-transection first approach in HL is a no-touch technique wherein liver transection is performed first, and the affected liver and hepatoduodenal ligament are removed en bloc. This approach allows for the early assessment of resectability and feasibility of vascular reconstruction4. ResultsThis video shows a 57-year-old man with advanced intrahepatic cholangiocarcinoma in the left hepatic lobe, which had directly invaded the perihilar region and the hepatoduodenal ligament via lymph node metastasis. The lymph node was extensively invasive into both the proper hepatic artery and portal vein. The case was initially deemed unresectable, but after three months of chemotherapy, conversion surgery was considered feasible. The common hepatic artery and gastroduodenal artery and then the common bile duct and main trunk of portal vein were secured at the pancreatic superior border. Hepatic dissection was performed along the Cantlie line. The right Glissonean pedicle was secured, including the right hepatic duct, right hepatic artery and right portal vein, and the operation was deemed feasible. The portal vein was dissected and reconstructed using the right external iliac vein. The left and caudate lobe with the middle hepatic vein and hepatoduodenal ligament were resected en bloc. Subsequentially, the common hepatic artery and right hepatic artery were reconstructed using the jejunal artery. ConclusionThe liver-transection first approach allowed us to determine the resectability of en bloc resection of the hepatoduodenal ligament at an early stage of surgery.