The assessment of the ASGE-grading system of ERCP: a large-sample retrospective study

Background and aims The American Society for Gastrointestinal Endoscopy (ASGE) has developed a complexity-grading system for endoscopic retrograde cholangiopancreatography (ERCP) to predict technical success and adverse events. This study aimed to assess the association between the degree of difficulty for ERCP and the rates of success and adverse event, in turn demonstrating the validity and practicality of this system. Methods ERCP procedures performed in the First Affiliated Hospital of Nanchang University from January 2010 to December 2019 were retrospectively reviewed. Procedural success and adverse events were recorded based on difficulty level according to the ASGE-grading system. Results A total of 20,652 ERCP procedures performed during the study period were analyzed, including 1908 procedures considered grade 1(9.2%), 10,170 procedures considered grade 2 (49.2%), 7764 procedures considered grade 3 (37.6%), 810 procedures considered grade 4 (3.9%). The overall success rate increased from 92.8% in 2011-2015 to 94.0% in 2016-2020, while the distribution of procedures and the incidence of complications showed little variation. The success rate revealed a significantly decreasing trend with increasing difficulty (ranging from 55.6 to 98.6%), mainly for biliary diseases. In addition, the difficulty scale was not associated with any differences in the rate of adverse event, except for the pancreatitis for grade 1 procedures, which had a low incidence. Conclusions The ASGE-grading system can help predict the success rate of ERCP procedures but showed poor performance in predicting adverse events. Further exploration may be required to improve the grading system by adjusting or including certain clinical parameters, and to validate the system for extrapolation to other endoscopy units.