Updates on Endoscopic Stenting for Unresectable Malignant Hilar Biliary Obstruction

Malignant hilar biliary obstruction (MHBO) can cause obstructive jaundice and/or cholangitis necessitating appropriate biliary drainage. Endoscopic biliary stenting is the first-choice treatment, especially in unresectable cases, owing to its minimally invasive nature and utility. However, the hilar region is complex because of the branching and curving of bile ducts, making strictures in this area more complicated. Therefore, MHBO stenting is challenging, and treatment strategies have yet to be established. Furthermore, recent advances in antitumor therapies have altered the background surrounding the development of stenting strategies. Therefore, it is necessary to understand and grasp the current evidence well and to accumulate additional evidence reflecting the current situation. This study reviews the current status, issues, and prospects of endoscopic stenting for MHBO, especially in unresectable cases.