Comparison of endoscopic ultrasound-guided choledochoduodenostomy and endoscopic retrograde cholangiopancreatography in first-line biliary drainage for malignant distal bile duct obstruction A multicenter randomized controlled trial

Introduction: In patients with malignant distal bile duct obstruction and normal gastrointestinal anatomy, endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS) is indicated when endoscopic retrograde cholangiopancreatography (ERCP) fails. The ERCP drainage route passes through the tumor, whereas the EUS-CDS route does not. Therefore, EUS-CDS is expected to have a longer stent patency than ERCP. However, for first-line biliary drainage, it remains unclear whether EUS-CDS or ERCP is superior in terms of stent patency. To reduce the frequency of highly adverse events (AEs) such as bile peritonitis or stent migration following EUS-CDS, we developed an antimigration metal stent with a thin delivery system for tract dilatation. This study is designed to assess whether EUS-CDS with this novel stent is superior to ERCP with a traditional metal stent in terms of stent patency when the two techniques are used for first-line drainage of malignant distal biliary obstruction. Methods/design: This study is a multicenter single-blinded randomized controlled trial (RCT) involving 95 patients in four tertiary centers. Patients with malignant distal biliary obstruction that is unresectable or presents a very high surgical risk and who pass the inclusion and exclusion criteria will be randomized to EUS-CDS or ERCP in a 1:1 proportion. The primary endpoint is the stent patency rate 180 days after stent insertion. Secondary outcomes include the rates of technical success, clinical success, technical success in cases not requiring fistulous-tract dilation (only EUS-CDS group), procedure-related AEs, re-intervention success, patients receiving post-drainage chemotherapy, procedure time, and overall survival time. Discussion: If EUS-CDS is superior to ERCP in terms of stent patency and safety for the first-line drainage of malignant distal biliary obstruction, it is expected that the first-line drainage method will be changed from ERCP to EUS-CDS, and that interruption of chemotherapy due to stent dysfunction can be avoided.