Endoscopic Ultrasound-Guided Biliary Drainage: Retrograde Approaches

Abstract

Endoscopic ultrasound (EUS) has several advantages over luminal procedures as it allows for access to structures which typically have no direct communication. Thus, in biliary obstruction, where endoscopic retrograde cholangiopancreatography (ERCP) has failed or is not technically possible due to post-surgical anatomy or malignant gastric outlet obstruction, EUS can be used to directly access the biliary system through the intestinal wall to assist with biliary drainage. There are two main methods of retrograde biliary drainage via EUS. The first method is also known as a “rendezvous” procedure and the second is via transluminal stenting, most commonly being choledochoduodenostomy. The EUS-guided rendezvous includes accessing the biliary system through the luminal wall into either the extrahepatic or intrahepatic bile duct in order to pass a guidewire antegrade down through the ampulla to be used for retrograde ERCP cannulation of the bile duct. The choledochoduodenostomy includes using lumen apposing metal stents for a direct communication of the biliary system and the duodenal lumen to allow for biliary drainage into the GI tract. Both methods have been found to be very safe and efficacious with high success rates and low rates of complication. Studies evaluating these procedures as first-line biliary decompressive strategies have shown promising results. However, further prospective trials will need to be performed. Most of the tools and devices used for these procedures are adapted from ERCP as there are very few on-label devices specific to EUS-guided biliary drainage. The development of more devices specific to these procedures will likely continue to reduce the procedural complications even further.