Use of combined laboratory and ultrasonography results to select patients for biliary tract imaging or intervention: a retrospective cohort study

Aim: To determine whether combined laboratory and ultrasonography results can be used to select patients for biliary tract imaging (BTI) or intervention. Background: Despite ongoing research, selection of patients with suspected CBD stone (CBDS) for BTI or direct intervention without imaging is still a subject of debate. Methods: Patients aged≥18 with symptomatic gallstone disease (SGD) who underwent MRCP over 3 years (2014-2017) were divided into the following cohorts: Group A: Normal liver enzymes with normal CBD diameter; Group B: Normal liver enzymes with dilated CBD; Group C: Isolated rise of liver enzymes with normal CBD diameter; Group D: Isolated rise of liver enzymes with dilated CBD; Group E: Hyperbilirubinemia with normal CBD diameter; Group F: Hyperbilirubinemia with dilated CBD. Binary logistic regression models were constructed for analyses. Results: Overall, 1022 patients were included. The frequency of CBDS was 7.2% in Group A; 3.8% in Group B; 6.3% in Group C; 22% in Group D; 24.2% in Group E; 47.4% in Group F. Hyperbilirubinemia with normal CBD (OR:1.52,P=0.010) and hyperbilirubinemia with dilated CBD (OR:5.12,P 0.001) independently predicted CBDS. Normal or isolated rise of liver enzymes with or without dilated CBD did not predict CBDS. Combined laboratory and ultrasonography had positive predictive value and negative predictive value of up to 47.37% and 100%, respectively. Conclusion: Patients with isolated rise of liver enzymes or hyperbilirubinemia with or without dilated CBD should undergo BTI prior to ERCP. Direct ERCP could be preserved for patients with high suspicion of CBDS where clinical features do not allow waiting for BTI.