The puzzle and challenge in the treatment of an intraoperative margin-positive proximal bile duct in hilar cholangiocarcinoma

Hilar cholangiocarcinoma (HCCA) is an uncommon neoplasm involving confluence of the hepatic ducts. Complete surgical resection (R0) is the only treatment with the potential for cure for HCCA (1). Over the past decades, the operative approach of HCCA has rapidly evolved, but in some cases, its anatomic location and longitudinal extent along the bile duct have made curative resection difficult. It remains controversial whether additional resection of the remaining proximal bile duct to obtain a negative resection margin when the frozen section (FS) examination of the proximal bile duct is positive. There is a consensus that cancer in situ (CIS) without invasive carcinoma at the duct margin is not related to poorer survival than a negative margin (2-5).