Endoscopic sphincterotomy (EST) combined with large balloon dilation (LBD) has been increasingly accepted as alternative method for removal of large bile duct stones. However, there were limited studies comparing the efficacy of EST in combined with LBD to EST with mechanical lithotripsy (ML). The purpose of this study to compare the efficacy and safety of combined EST- LBD versus EST-ML in the removal of very large bile duct stones.

The large common bile duct stones (CBDS) remains a therapeutic challenge in ERCPs. Large CBDS are generally refractory to be removed by EST and stone extraction balloons and or baskets. Traditional rescue therapy was the technique of stone fragmentation using ML. The previous reports have shown that EST with ML was successful in the fragmentation of large stones yielding stone clearance rate from 68 t0 79 %. EST-LBD has been shown favorable outcome in the treatment of large bile duct stone. A meta-analysis comparing the effectiveness and complications between EST-LBD and EST in the management of CBDS showed that EST-LBD was as effective as EST for the removal of large or difficult of CBDS in terms of stone clearance in the first ERCP session of 87.87 % vs. 84.15 % and overall clearance of 97.35 % vs. 96.35 % but EST-LBD was associated with fewer complications as well as reduced need for ML compared to EST. The efficacy of EST-ML versus EST-LBD as a therapy for relatively large CBDS, a mean stone size > 20 mm in currently not well defined. The investigators, herein, compared the efficacy and complications between EST followed by LBD or ML for the removal of CBDS > 15 mm with a mean stone size > 20 mm.

Inclusion Criteria: -Patients with age>/= 18 years with confirmed or suspected CBDS at our institute were enrolled in the study.

• Informed consent was obtained in every patients prior to the procedure
• Patients were randomized to LBD or ML if they had CBD stone >/= 15 mm in shortest dimension or stone' size was disproportionate to the lower bile duct segment with a ratio of largest stone dimension/lower bile duct segment diameter > 50 % identified by a cholangiogram at ERCP.

Exclusion Criteria:-pregnant woman

• uncorrectable coagulopathy (INR >1.5 ), thrombocytopenia( platelet count < 50,000)
• concomitant intrahepatic duct stones
• ongoing acute pancreatitis or acute cholecystitis
• surgically altered anatomy (i.e. Billroth II or Roux-en-Y reconstruction)
• concomitant pancreatic or biliary malignancy

The individual data of patients participating in the study are not available for public sharing since we did not obtain the consent to share the data of patient