the factors contributing to the failure of choledochoscopy , thus far , to prevent all retained stones are identified as inexperience of surgeons learning to perform biliary endoscopy , failure to scan the biliary tree systematically and thoroughly ( including the left hepatic duct ) , and failure to reach the duodenum with the choledochoscope , meaning failure to see the lower segment of the common duct and ampullary orifice .
C0005423
biliary tree
C0227560
left hepatic