To explore the treatment of giant impacted bile duct stones by electrohydraulic lithotripsy with the "mother-baby" endoscopic system and mechanical lithotripsy.

For giant impacted bile duct stones treated difficultly by standard ERCP techniques, stones fragmentation by electrohydraulic lithotripsy with the "mother-daughter" endoscopy system were performed firstly and the bile duct were cleared by mechanical lithotripsy secondly.

All 21 cases underwent "mother-daughter" endoscopy successfully. The stones of 18 cases with extrahepatic duct stones were all extracted, 14 cases underwent once stone extraction, 4 cases underwent twice stone extraction. In 3 cases with left and right hepatic duct impacted stones, the stones of 2 cases were all extracted, there were residual intrahepatic duct stones in 1 cases with multiple impacted right intrahepatic duct stones. 3 cases had minor transient bleeding, 1 cases had cholangitis,2 cases had post-ERCP pancreatitis, no serious complications of perforation, fatalities occurred.

For giant impacted bile duct stones treated difficultly by standard ERCP techniques, the combination of electrohydraulic lithotripsy by the "mother-baby" endoscopy system with mechanical lithotripsy is a safe and effective treatment.