Predictors of recurrent bile duct stone after clearance by endoscopic retrograde cholangiopancreatography:A case-control study

Background:Recurrent common bile duct(CBD)stone is a long-term sequalae among patients who un-derwent endoscopic retrograde cholangiopancreatography(ERCP)with CBD stone extraction.Data regard-ing risk factors for recurrent CBD stone are scarce.We aimed to identify predictors of recurrent CBD stone.Methods:We performed a retrospective case-controlled study from January 2010 to December 2019.In-clusion criteria included patients who had recurrent CBD stone at least 6 months after the index ERCP,in which complete stone extraction was performed and normal cholangiogram was obtained.Overall,457 patients were included.Forty-two patients(9.2%)had recurrent CBD stone,and 415 patients(90.8%)did not have recurrent CBD stone.Results:In univariate analysis,male sex[odds ratio(OR)=0.49,P=0.033]was a protective factor,while endoscopic stone extraction by basket vs.balloon(OR=2.55,P=0.005),older age(OR=1.03,P=0.003),number of CBD stones(OR=1.99,P=0.037),size of CBD stone(OR=4.06,P=0.003)and mechanical lithotripsy(OR=9.22,P=0.004)were risk factors for recurrent CBD stone.In multivariate logistic regression analysis,mechanical lithotripsy[OR=9.73,95%confidence interval(CI):1.69-55.89,P=0.010],basket clearance vs.combined basket and balloon(OR=18.25,95%CI:1.05-318.35,P=0.046)and older age(OR=1.02,95%CI:1.00-1.05,P=0.023)were risk factors,and male sex(OR=0.39,95%CI:0.19-0.81,P=0.012)was a protective factor.