Biliary stone extraction during ERCP: Analysis of factors that influence successful stone extraction

Aim: To review the endoscopic management of biliary stones at a tertiary referral center and determine the factors that influence successful stone extraction. Method: All ERCP's performed for biliary stone extraction over the last 7 years were reviewed using our endoscopy database. Results: 1426 consecutive ERCP's were performed over the last 7 years. Of those, 157 were performed in 118 patients with the intent of removing a biliary stone. Of the 118 patients, 33 were males (28%) and 85 were females (72%). The mean age was 57.4 years. Prior sphincterotomy(SP) was found in 30 patients (25.4%) and extension of the SP was performed in 16 patients. A standard SP was performed in 86 patients (72.9%). Nine underwent needle knife SP. Six patients had balloon dilation of the sphincter. Of the 118 patients, 88 had successful stone extraction at the initial ERCP (74.6%). The mean stone size in these patients was 8 mm (2 to 20). Thirty patients required more than one ERCP in an attempt to clear the bile duct (25.4%). The mean stone size in these patients was 13.4 mm (5 to 25). The total success rate of endoscopic stone extraction was 96%. The devices used for stone extraction were the balloon (BL) catheter, stone basket (BK) and mechanical lithotripter (ML). At initial ERCP, BL was used in 91 cases (87.3%). BK was used in 22 cases (19.5%) and ML was used in 16 cases (13.6%.). Of the 30 patients who underwent a subsequent ERCP. 25 had successful clearance of their ducts. In addition to BL, BK and ML, extracorporeal shock wave lithotripsy (ESWL) was required in 5 patients, cholangioscopy/electrohydraulic lithotripsy (EHL) in 4 and laser lithotripsy in 1. Of those patients who failed stone extraction, 4 were referred for surgery : 2 had a stone larger than 2cm, 1 had multiple intrahepatic duct stones and 1 had a stone lodged in a biliary diverticulum. Complications included mild pancreatitis (0.9%), mild bleeding (3.4%), failed cannulation (0.9%), and death unrelated to the procedure (0.9%). Conclusions: Endoscopic stone extraction was successful in 96% of patients. ESWL and EHL were measures used after the initial methods failed. In those who failed endoscopic stone extraction, size and location of the stone influenced the success of the procedure. The complication rate for stone extraction was low.