Diagnostic Guidelines for the Evaluation of Choledocholithiasis in Patients With Acute Biliary Presentations: A Study of Their Applicability and Feasibility in a Publicly Funded Healthcare System

Background The American and European Societies of Gastrointestinal Endoscopy (ASGE and ESGE) have published diagnostic guidelines for the evaluation of choledocholithiasis. The applicability and feasibility of these guidelines in a publicly funded health care system, such as ours in Aotearoa New Zealand, are not known. This retrospective study compared the diagnostic performance and utility of these guidelines against our current approach to biliary investigations to explore the feasibility of their local implementation. Methods We identified patients with biliary diagnosis during 2017 from admission records. We retrospectively applied the diagnostic criteria of the ASGE 2010, ASGE 2019 and ESGE 2019 guidelines to classify patients as low, intermediate or high risk for choledocholithiasis, and to determine their management if the guidelines were followed. We estimated the diagnostic performance of the guidelines using ERCP or IOC as gold standard. The simulated volume and diagnostic yield of biliary investigations according to guidelines were compared to those observed with our current approach. Results We included 621 patients, of whom 18% had choledocholithiasis. For diagnosing choledocholithiasis, ASGE 2010, ASGE 2019 and ESGE 2019 guidelines had sensitivities of 79%, 68% and 57% and specificities of 93%, 96% and 97% respectively, if only patients classified as high risk were considered. If patients classified as high or intermediate risk were both considered, their sensitivities increased to > 99% at the expense of lower specificities of 20%–30%. The AUCs for the guidelines were 0.88, 0.85 and 0.83, respectively. When compared to our current approach to biliary investigations, guideline adoption would double MRCP utilisation with correspondingly decreased diagnostic yield. Conclusion Both ASGE and ESGE guidelines for choledocholithiasis may increase the volume of biliary investigations without delivering better diagnostic performance than an ad hoc approach to biliary investigations. Guideline adoption in their current forms cannot be justified in our publicly funded system in Aotearoa New Zealand. Possible contributors to poor guideline performance have been proposed and these will require further research to guide adaptation of the guidelines for our local use.