Primary needle-knife fistulotomy for preventing post-endoscopic retrograde cholangiopancreatography pancreatitis: importance of the endoscopist’s expertise level

Abstract Background Needle-knife fistulotomy (NKF) is used as a rescue technique for difficult cannulation. However, the data are limited regarding the use of needle-knife fistulotomy for primary biliary cannulation, especially when performed by beginners. To assess the effectiveness and safety of primary NKF for biliary cannulation, and the role of the endoscopist’s expertise level (beginner vs. expert). Methods We retrospectively evaluated the records of 613 patients with naïve papilla and no history of pancreatitis, who underwent bile duct cannulation at a tertiary referral center. The patients were categorized according to the endoscopist’s expertise level and the technique used for bile duct cannulation. We assessed the rates of successful cannulation and adverse events. Results The baseline characteristics did not differ between the pre-defined groups. The incidence rate of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) was significantly affected by the endoscopist’s expertise level in patients who received conventional cannulation with sphincterotomy (11.3% vs. 5.7% for beginner vs. expert, P =0.033), but not in those who received NKF. In the multivariable analysis, a lower expertise level of the biliary endoscopist and longer cannulation time were significant risk factor of post-endoscopic retrograde cholangiopancreatography pancreatitis ( P =0.030, P =0.005) in patients who received conventional cannulation with sphincterotomy but not in those who received NKF. Conclusion Compared to conventional cannulation with sphincterotomy, primary NKF carries a lower risk of PEP regardless of the endoscopist’s level of expertise. Primary NKF may be effective and safe in achieving ductal access in patients with naïve papilla.