Active_comparator: EUS-guided rendezvous group (EUS RV group)

In the EUS RV group, a linear array echoendoscope would be used to evaluate the common bile duct and left intrahepatic duct in order to identify the optimal route for biliary access by fine needle. Using a 19 gauge EUS needle, the dilated biliary tree will be accessed by either a transduodenal puncture to the common bile duct or a transgastric puncture to the left intrahepatic duct under direct EUS guidance. The optimal access route will be based on patient's anatomy after EUS assessment and left to the discretion of the investigator. Next, a guidewire would be advanced through the needle into the bile duct and out of the papillary orifice. The echoendoscope would then be exchanged to a duodenoscope for ERCP. The EUS rendezvous ERCP procedure will be completed by retrieving the rendezvous guidewire into the duodenoscope or by cannulation alongside the rendezvous guidewire to obtain biliary access.

Active_comparator: Early precut papillotomy group (EPP group)

In the EPP group, the precut papillotomy would be performed with 1 of the following acceptable techniques per the usual practice of the study investigator and institution: 1) conventional precut papillotomy by needle knife, 2) precut fistulotomy by needle knife, or 3) transpancreatic precut papillotomy by papillotome