Background: Deep cannulation of the common bile duct (CBD) in patients with native papillary anatomy can be used as a marker of competence at ERCP.

Objective: The primary aim of this study was to analyze a single-operator learning curve for supervised ERCPs in patients with native papillary anatomy and to assess the development of endoscopic competence, defined as the ability to deeply cannulate the CBD in the setting > or =80% of the time. Posttraining outcomes were evaluated as proof of training.

Design: A retrospective review: 1097 ERCP procedures were analyzed, 697 were performed during ERCP training (July 2002-July 2003), 400 were performed after training as an independent operator, 499 and 303 procedures for training and posttraining periods, respectively, were performed with the intent of deep cannulation of CBD in patients with native papillary anatomy. Procedures were chronologically grouped into subsets. Success rates were plotted against time.

Setting: Single center.

Main outcome measurements: Rate of successful deep biliary cannulation.

Results: The successful cannulation rate increased from 43% at the beginning of training to > or =80% after 350 to 400 supervised procedures. The success rate continued to improve posttraining with an aggregated success rate of >96% for the next 300 procedures performed as an independent operator.

Limitations: Single operator.

Conclusions: Achievement of a satisfactory success rate for deep biliary cannulation in patients with native papillary anatomy should be tracked by ERCP trainers and trainees. The consistent achievement of > or =80% success at deep biliary cannulation in such patients should become a standard for ERCP training programs to produce skilled and competent therapeutic biliary endoscopists.