Fb 39q

All procedures were performed using standardized protocols by two experienced investigators using a standard duodenoscope (JF or TJF‐260V; Olympus Medical System Co., Ltd., Tokyo, Japan) with the patients under conscious sedation. Standard techniques were used to cannulate the biliary tract, and contrast (Omnipaque; GE Healthcare, Seoul, Korea) was injected to identify the location and length of the stricture. For all patients, IDUS was performed followed immediately by cholangiogram. The IDUS probe (UM‐G20‐29R; Olympus Medical System) was 2.0 mm diameter and had a radial scanning catheter with a scanning frequency of 20 MHz. The catheter had a monorail‐type design at the tip, which facilitates its passage over guide wires. The IDUS probe was inserted into the bile duct under endoscopic and fluoroscopic guidance over a guide wire without endoscopic sphincterotomy (EST). IDUS imaging was performed during probe withdrawal and stricture dilation was not performed for the IDUS examination. The TPB of the biliary stricture was obtained under fluoroscopically guided retrograde biliary biopsy during ERCP after EST. TPB yielded four to six specimens using forceps with a 1.8‐mm‐diameter cup (FB‐39Q; Olympus Medical System). The remainder of the ERCP procedure was then performed according to the individual needs of each patient.