Comprehensive evaluation of endoscope performance involves balanced assessment, accurate feedback, and suggested improvements by endoscopists

Endoscopic retrograde cholangiopancreatography (ERCP) techniques have advanced considerably because of the continuous development and improvement of devices. For the safe and reliable performance of endoscopic techniques, acquisition and improvement of adequate skills by endoscopists, and improvement and development of devices and endoscopes are essential. Manufacturers have continuously and heavily invested in the research and development of endoscopes. Each manufacturer uses various methods to conduct their research and development; however, there has been no standard evaluation method for the technical performance of endoscopes. In this issue ofDigestive Endoscopy, Bang et al. proposed a tool for assessing the performance of duodenoscopes and prospectively validated its usefulness. Specifically, they used this tool to assess the performance of duodenoscope for ERCP interventions in 1080 patients at nine academic centers. Among the assessed parameters, the authors evaluated endoscopic maneuverability, mechanical/imaging characteristics, and the ability to perform interventions on a 5point scale. Endoscopic maneuverability was closely evaluated in terms of insertion into the esophagus, passage through the stomach and pylorus, achievement of short position, and appropriate distance from the papilla. Moreover, ERCP was evaluated separately for biliary and pancreatic interventions to determine the ease and successful completion of the procedure. Coefficient alpha was used to calculate the reliability of these evaluations. The coefficients were 0.81 overall, 0.92 for mechanical/imaging characteristics, and 0.81 for the ability to perform requisite interventions, all of which indicated a high consistency with performance. Bang et al. concluded that their assessment tool was sufficiently reliable. Multiple linear regression analysis identified prolonged procedure durations, older age of patients, and pancreatic interventions as factors associated with a higher (worse) score. Thus, the assessment tool reported by Bang et al. appears to be effective and fairly reliable. However, although it may be useful for evaluating the performance of endoscopes, several issues need to be considered. First, Bang et al. only assessed the usefulness of their assessment tool for evaluating the performance of duodenoscopes TJF-180 (Olympus Co., Tokyo, Japan). They used the therapeutic duodenoscope for the included patients, and correlations between the scores and performance were evaluated. It is considered that the validity of an assessment tool can be tested by repeatedly using the same endoscope in the same population to confirm the reproducibility of scores. However, in clinical practice, it is difficult to evaluate the reproducibility of scores by repeatedly using the same duodenoscope in the same patients. Alternatively, different duodenoscopes can be used to examine whether the scores differ when calculated using a scoring system. Second, the most important aspect for a reliable evaluation is thehomogeneityof the evaluating endoscopists even though they are experts in the procedure. Usually, assessment is first evaluated and eventually validated by experts. Then this validation needs to be also done in non-experts to explore the reproducibility of the results found by experts. In the study, endoscopists at tertiary referral centers performed the assessments of endoscopes. Although these centers were stratified into university and non-university hospitals, all of them were high-volume centers where highly skilled endoscopists performed the assessments of endoscopes. In addition, the scores for most parameters were low; thus, the performance of the endoscopeswas judged to be excellent. Indeed, to examine the reliability of an assessment tool, endoscopists with a certain level of skill should perform the endoscopic techniques. However, such endoscopists can complete the endoscopic techniques using any type of endoscope. Pancreatobiliary endoscopy is a technically challenging procedure, but all highly skilled endoscopists do not perform it regularly. Therefore, further studies may be needed to determine the applicability and reliability of the assessment tool describedby Bang et al. for beginners and intermediate endoscopists. Third, Bang et al.’s study excluded cases of failed cannulation. They stated that the exclusion of such cases is valid to accurately evaluate all parameters. In addition, biliary cannulation failed in only 28 cases (2.5%), showing a high