Reply to Sundaram et al.

We would like to thank Sundaram et al. [1] for their interest and comments regarding our recent publication “Difficult biliary cannulation in ERCP procedures with or without trainee involvement: a comparative study” [2].

In past decades, multiple efforts have been made to evaluate the skills and competence of trainees during endoscopic retrograde cholangiopancreatography (ERCP) training [3] [4]; however, the quantitative and objective assessment remains problematic. Owing to the retrospective nature of our study, the skills of trainees prior to ERCP training could not be ascertained. As Voiosu et al. [5] showed in their prospectively cohort study, ERCP skill may be dynamically improved during the training process. The definition of difficult cannulation in trainee-involved procedures may be influenced by the learning curve effect and different levels of skill.

As Sundaram et al. point out, documentation of procedure-related variables would have been tedious. In our center, these data were prospectively collected by one of two investigators not involved in the ERCP procedure, which made it possible to evaluate the cannulation procedure precisely. The documentation of procedure-related variables is valuable as the data are important for the definition of difficult cannulation and useful for determining whether or when advanced cannulation techniques should be chosen. Our study showed that overall cannulation time was highly related to number of attempts. Therefore, two simplified criteria (5–1 vs. 5–5–1 for the non-trainee group and 15–2 vs. 15–10–2 for the trainee group) were further proposed, with the purpose of reducing the tedious work of real-time data recording.

In this study, we performed a propensity score matching (PSM) analysis. Propensity scores to determine matched pairs between the groups were created using nine variables that could potentially influence the cannulation difficulty. After PSM, different criteria of non-trainee vs. trainee group were proposed. More advanced cannulation methods were observed in the trainee group compared with the non-trainee group, especially with regard to the double-guidewire cannulation technique (8.5 % vs. 2.8 %; P < 0.001). This may be mainly due to the longer total cannulation time (7.5 minutes vs. 2.0 minutes), more cannulation attempts (5 vs. 2), and inadvertent pancreatic duct cannulation (0 [interquartile range [0–2] vs. 0 [0–1]) in the trainee group compared with the non-trainee group. With the time prolonged and the pancreatic duct entered, it is not surprising that the double-guidewire technique was used more frequently in the trainee group.

Finally, we agree with Sundaram et al. that the reliability of the criteria deserves to be further validated in prospective studies in order to provide more credible evidence for wide acceptance of these novel criteria in clinical practice.

Publication History

Article published online:
24 November 2021

• References

• 1 Sundaram S, Kale A. Trainee involvement in ERCP – new criteria to simplify a complex problem. Endoscopy 2021; 53: 1288
• 2 Wang X, Luo H, Tao Q. et al. Difficult biliary cannulation in ERCP procedures with or without trainee involvement: a comparative study. Endoscopy 2021; DOI: 10.1055/a-1523-0780.
• 3 Siau K, Dunckley P, Feeney M. et al. ERCP assessment tool: evidence of validity and competency development during training. Endoscopy 2019; 51: 1017-1026
• 4 Voiosu T, Bălănescu P, Voiosu A. et al. Measuring trainee competence in performing endoscopic retrograde cholangiopancreatography: a systematic review of the literature. United European Gastroenterol J 2019; 7: 239-249
• 5 Voiosu T, Bengus A, Voiosu A. et al. Trainee caseload correlates with ERCP success rates but not with procedure-related complications: results from a prospective study (the QUASIE cohort). Endosc Int Open 2016; 04: E409-E414