SEMS insertion for hilar stricture: Who, when, and why?

Hilar strictures are narrowings at the bifurcation of the right and left hepatic duct and are most commonly caused by malignant etiologies, specifically cholangiocarcinomas. Patients who initially present with hilar strictures should be worked up to rule out malignancy, and if malignancy is suspected, it should be discussed in a multidisciplinary setting to assess whether they are candidates for surgical resection or liver transplant. In potential surgical candidates, the role of preoperative biliary drainage should be individualized based on clinical presentation and timing of surgery. In unresectable hilar strictures, either percutaneous or endoscopic biliary drainage may be performed. Endoscopic biliary drainage can be done with the placement of plastic or self-expanding metal stents, with more recent evidence supporting the use of SEMS. The decision to perform unilateral or bilateral drainage should factor in liver volume, and a goal of draining at least 50% of liver volume should be sought. Methods to insert SEMS include side-by-side insertion and stent-in-stent insertion. Recent advances have allowed easier and more proximal insertion of SEMS. Overall, the clinician should take into account multiple aspects including patient factors, anatomy, etiology, stricture location, and endoscopic familiarity when treating hilar strictures.