The learning curve for needle knife precut sphincterotomy revisited

Background There is no consensus on what constitutes adequate training for needle knife precut sphincterotomy. Objective The purpose of this study was to determine the number of procedures required before effective and safe precut sphincterotomy can be achieved. Methods This retrospective study examined the cumulative experience of a single endoscopist from January 2006-December 2015. Precut sphincterotomy success and complication rates were analyzed as a function of number of procedures performed. Acceptable success and complication rates were defined as 85% and 10% respectively. A one-sided binomial test was used to test success and complication rates of every 25 precut sphincterotomies performed. Results The index endoscopic retrograde cholangiopancreatography was successful in 141/158 (89.2%) patients who underwent precut sphincterotomy. This increased to 148/158 (93.7%) when endoscopic retrograde cholangiopancreatography was repeated on another day. Six precut sphincterotomies were required to achieve an 85% success probability. This was maintained consistently above 85% after 13 precuts, and was significantly higher (91.2%; p=0.029) than 85% at the 125th precut. Bleeding and pancreatitis developed in 2/158 (1.3%) and 5/158 (3.2%). Probability of either complications remained below 5% after 50 precuts. No perforation occurred. Conclusion At least 13 precut sphincterotomies were required to achieve a sustained success rate greater than 85%. The probability of bleeding or pancreatitis was less than 5% after 50 precut sphincterotomies.