Difficult Biliary Cannulation in Endoscopic Retrograde Cholangiopancreatography: Definitions, Risk Factors, and Implications.

Over the past 50 years, endoscopic retrograde cholangiopancreatography (ERCP) has become the preferred minimally invasive method of treating a vast array of pancreatobiliary diseases. An initial sine qua non for ERCP success is selective ductal cannulation. Despite significant progress in the optimisation of ERCP methods and accessories, selective biliary cannulation using conventional techniques remains unsuccessful in approximately 15% of native papilla cases. Furthermore, difficult biliary cannulation has been associated with an increased risk of post-ERCP pancreatitis, among other adverse events. Here, in the first of a two-part series, the authors provide a primer on standard biliary cannulation techniques and discuss the definition, risk factors, and implications of difficult biliary cannulation. The second part of the series will provide an overview of the existing advanced techniques used in cases of difficult biliary cannulation as well as the approach to their selection.