ERCP Mechanical Simulator (EMS) Practice Enhances Traineesʼ Success with Common Bile Duct (CBD) Cannulation

Abstract

Purpose: Background: EMS practice in the early stage of clinical ERCP training has been reported to be beneficial (GIE 2009; 69:AB141). Its role in augmenting performance of trainees with some clinical ERCP experience is unknown. Hypothesis: EMS practice is a predictor of success in CBD cannulation when introduced to EMS naive trainees after 6 months of usual clinical training.Table 1: Success with deep CBD cannulationTable 2: Factors associated with success of selective CBD cannulation by trainees (GEE analysis)Methods: Design: A randomized controlled cross-over study. 8 trainees attended didactic lectures on ERCP. Randomization was stratified based on site (n=2). Study group (SG) trainees participated in a one day handson simulator practice of selective bile duct cannulation supervised by JWL. Control group (CG) trainees did not participate in EMS practice. Subsequent clinical ERCP performance of all trainees was documented objectively. Primary outcome was successful deep CBD cannulation (0=fail, 1=success). After 6 months, CG trainees were crossed over to participate in one session of EMS practice. Performance of all trainees was tracked for another 6 months. The primary outcome was correlated to EMS practice status (with or without), overall clinical ERCP experience (days entered into ERCP training) and level of difficulty (normal papilla, diverticula, prior papillotomy or stenting) for CBD cannulation. Statistical analysis was performed using generalized estimation equations (GEEs) to fit the parameters of a generalized linear model where unknown correlations are present. The equations allow for correlation without explicitly defining a model for the origin of the dependency and are most suitable when the random effects and their variances are not of direct interest. The average response over the population (“population-averaged” effects) is estimated rather than the regression parameters that would enable prediction of the effect of changing one or more components of an unknown factor on a given individual. Results: Deep CBD cannulation was attempted in 153 of 224 and 142 of 225 cases in each of the two consecutive 6 months period, respectively. The table summarizes the odds ratio of trainee success in deep CBD cannulation taking all pre and post crossover data into consideration. EMS practice is a significant factor in predicting success while difficult papilla predicts cannulation failure. Conclusion: A single session of EMS practice enhances the success rate of CBD cannulation regardless of when it is introduced - at the beginning or after 6 months of usual clinical training. The results provide evidence to support the use of mechanical simulator practice, offered at the beginning or midway through clinical ERCP training, to augment the ERCP training experience. Disclosure: Cook Endoscopy - educational grant and equipment support Olympus America - educational grant and equipment support Dr Joseph Leung is supported by Cook Asia (speakers honorarium) during his sabbatical leave to conduct the research study in Taiwan. Partial research funding support from ACG Research Grant. This research was supported by an industry grant from Cook Endoscopy and Olympus Tokyo provided equipment support for simulator practice. The ERCP mechanical simulator is not commercially available and is used for teaching and research purposes.