Objectives: The reported incidence of adverse events (AEs) in endoscopic retrograde cholangiopancreatography (ERCP) varies between 2.5% and 14%. The aim of this study was to evaluate the incidence and severity of AEs in biliary ERCP and to specify the risk factors and preventive measures for post‐ERCP pancreatitis (PEP).Methods: Patients with biliary disease with intact papilla were prospectively enrolled at 36 hospitals between April 2017 and March 2018. The primary outcomes were the incidence and severity of AEs.Results: A total of 16,032 ERCP procedures were performed at the 36 hospitals during the study period and 3739 patients were enrolled. The overall incidence of AEs was 10.1% and ERCP‐related mortality was 0.08%. PEP developed in 258 cases (6.9%), bleeding in 33 (0.9%), instrumental AEs in 17 (0.5%), infections in 37 (1.0%), cardiovascular AEs in eight (0.2%), pulmonary AEs in eight (0.2%), drug reaction AE in one (0.03%), pain in 15 (0.4%), and other AEs in 15 (0.4%). Multivariable analysis showed significant risk factors for PEP were: female of younger age, pancreatic guidewire‐assisted biliary cannulation, temporary guidewire insertion into the pancreatic duct, total procedure time >60 min, and post‐ERCP administration of non‐steroidal anti‐inflammatory drugs. Effective preventive measures were prophylactic pancreatic stenting (PPS) and epinephrine spraying onto the papilla.Conclusions: In patients with intact papilla who underwent biliary ERCP, the incidence of AEs was 10.1% and the mortality was 0.08%. PPS and epinephrine spraying may prevent PEP.Registration: This study was registered in the University Hospital Medical Information Network (UMIN000024820).

Background and Aim: Post‐endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) is the most serious adverse event of ERCP. Therefore, it is important to identify high‐risk patients who require prophylactic measures. The aim of this study was to develop a practical prediction model for PEP that identifies high‐risk patients.Methods: Patients who underwent ERCP at three tertiary hospitals between April 2010 and September 2012 were enrolled. The dataset was divided into a training set (two centers) and validation set (one center). Using the training set, univariable and multivariable analyses were performed to identify predictive factors for PEP. We constructed a scoring system and evaluated reproducibility using the validation set.Results: A total of 2719 ERCPs were analyzed. PEP developed in 133 cases (4.9%). Risk factors (adjusted odds ratios [OR]) in the training set were a history of PEP (OR: 4.2), intact papilla (OR: 2.4), difficult cannulation (OR: 1.9), pancreatic guidewire‐assisted biliary cannulation (OR: 2.2), pancreatic injection (OR: 2.1), pancreatic intraductal ultrasonography (IDUS)/sampling from the pancreatic duct (OR: 2.2), and biliary IDUS/sampling from the biliary tract (OR: 2.8). A scoring system was constructed using these seven clinical variables. The areas under the receiver‐operating characteristic curve of this model were 0.799 in the training set and 0.791 in the validation set. In the high‐risk group at a score of 3 or higher, the incidence of PEP was 13.4%, and all severe/fatal cases were in the high‐risk group.Conclusions: This scoring system helps to predict each patient's risk and select preventive measures.

Endoscopic sphincterotomy (ES) is an established method to treat common bile duct (CBD) stones. Inevitable sequence after ES is a substantial risk of recurrent choledocholithiasis and occasional difficulty in removal of large or multiple CBD stones after ES even when mechanical lithotripsy (ML) is employed. In turn, a new endoscopic technique, large balloon dilation (LBD) after ES, has been introduced. The objective was to analyze the efficacy and safety of LBD in patients with recurrent bile duct stones who have previously undergone ES.From December 2007 to November 2009, 24 patients with recurrent choledocholithiasis and a history of ES were treated with LBD without additional ES. The size of the balloon for LBD was 15-20 mm and the duration of balloon dilation was 30 s.Successful stone removal and complications such as perforation, pancreatitis, and bleeding were evaluated as procedure-related outcomes. Postoperative CBD stone recurrence was evaluated as the short term outcome. Complete duct clearance rate without using ML was 96% (23/24 patients) and all stone removal was achieved in one session. Failure to remove stones occurred in one (4.2%) patient. There were no procedure-related complications although one case of aspiration pneumonia occurred after the endoscopy. Recurrent choledocholithiasis after LBD was observed in 12.5% (3/24) of the cases overall.LBD is an effective and safe method in patients with recurrent choledocholithiasis not only to treat large stones but also to prevent further recurrence.