title: Topic controversies in the endoscopic management of malignant hilar strictures using metal stent: side-by-side versus stent-in-stent techniques.
abstract: Endoscopic management of unresectable hilar malignant biliary stricture (MBS) is currently challenging, and the best approach is still controversial. Liver volume is the key to adequate biliary drainage in hilar MBS and multiple stenting is mandatory to drain over 50% of liver volume in most cases. The self-expandable metallic stent (SEMS) has shown superior patency to plastic stents in recent reports. There are two methods of multiple stenting for hilar MBS: stent-in-stent (SIS) and side-by-side (SBS). Advantages of SIS include multiple SEMS placement in one stent caliber at the common bile duct (CBD), which is considered physiologically ideal. The through-the-mesh (TTM) technique with guidewires and the SEMS delivery system can be technically difficult in SIS, although the recent development of dedicated SEMSs having a loose portion facilitating the TTM technique makes SIS technically feasible both at stent deployment and re-interventions. Conversely, the SBS technique, if placed across the papilla, is technically simple at initial placement and re-intervention at stent occlusion. However, SBS has potential disadvantages of overexpansion of the CBD because of parallel placement of multiple SEMS, which can lead to portal vein thrombosis. Given the limited evidence available, a well-designed randomized controlled trial comparing these two techniques is warranted.
authors.affiliation: Digestive Disease Center and Research Institute, Department of Internal Medicine, Soonchunhyang University School of Medicine, Bucheon, Korea.
authors.forename: Jong Ho
authors.initials: JH
authors.lastname: Moon
authors.affiliation: Division of Gastroenterology, Department of Medicine, Chulalongkorn University, Bangkok, Thailand.
authors.forename: Rungsun
authors.initials: R
authors.lastname: Rerknimitr
authors.affiliation: Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Kogure
authors.affiliation: Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
authors.forename: Yousuke
authors.initials: Y
authors.lastname: Nakai
authors.affiliation: Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Isayama
mesh_terms: D001650:Bile Duct Neoplasms / Q000150:complications* / Q000601:surgery; D001662:Biliary Tract Surgical Procedures / Q000379:methods*; D002779:Cholestasis / Q000209:etiology / Q000601:surgery*; D016145:Endoscopy, Digestive System / Q000379:methods*; D006801:Humans; D010166:Palliative Care; D011474:Prosthesis Design; D015607:Stents; D016896:Treatment Outcome
keywords: Biliary stent; Biliary stricture; Endoscopic procedure; Hilar stricture; Self-expandable metal stent