Comprehensive review on EUS-guided biliary drainage.

Feasibility of endoscopic retrograde cholangiopancreatography (ERCP) for biliary drainage is not always applicable due to anatomical alterations or to inability to access the papilla. Percutaneous transhepatic biliary drainage has always been considered the only alternative for this indication. However, endoscopic ultrasonography-guided biliary drainage represents a valid option to replace percutaneous transhepatic biliary drainage when ERCP fails. According to the access site to the biliary tree, two kinds of approaches may be described: the intrahepatic and the extrahepatic. Endoscopic ultrasonography-guided rendez-vous transpapillary drainage is performed where the second portion of the duodenum is easily reached but conventional ERCP fails. The recent introduction of self-expandable metal stents and lumen-apposing metal stents has improved this field. However, the role of the latter is still controversial. Echoendoscopic transmural biliary drainage can be challenging with potential severe adverse events. Therefore, trained endoscopists, in both ERCP and endoscopic ultrasonography are needed with surgical and radiological backup.