[Clinical and experimental studies on stone detectability of cholangiography and choledochoscopy. Prevention of retained biliary-tract stones].

UNLABELLED: Preoperative diagnostic accuracy was significantly improved following a recent development of diagnostic imaging techniques. However, the incidence of retained biliary tract stones is far from satisfactory low. Retrospective studies on operative and postoperative cholangiography, and choledochoscopy were carried out to determine the limitation of each modality in preventing the retained biliary tract stones. The effectiveness of postoperative stone extraction technique for retained biliary tract stones was reevaluated by a follow up study of 213 cases with retained biliary tract stones in which complete removal of the stones was considered to be successful. Finally, a radiological experimental study concerning stone detectability was carried out using phantom system.

CONCLUSION: 1) In the retrospective study of operative cholangiography, stones were not demonstrated on cholangiograms in 78 out of 167 cases, although they were detected and extracted by postoperative choledochoscopy. The main causes of the failure of cholangiography were the administration of highly concentrated contrast material (47.4%) and incomplete filling of whole ducts (26.9%). Therefore, the further development for the detection of these stones by operative cholangiography should be desired. 2) In the experimental study, it was clarified that complete filling of the ducts with 30% or 20% contrast materials was essential in normal size or dilated ducts respectively in order to detect small size stones. Moreover, the author emphasized that it is important to take two photographs, one is taken at proper voltage and the other at voltage 10 kVp. Higher in order to demonstrate whole stones whose sizes are varied. 3) Stone detectability was improved to 87.1% by using both operative cholangiogram and choledochoscopy. 4) Routine use of postoperative choledochoscopy at the time of T-tube removal is essential, because stone not detected by T-tube cholangiography were found endoscopically in 2.2% of cases with retained stones. 5) In the follow-up study, a good result was obtained in the cases in which complete stone extraction was considered to be successful by postoperative choledochoscopy. However, reoperation was found to have been performed in 13 cases, because of recurrent or retained stones. Of them three cases were judged to be recurrence. In the other 10 cases, the stones were defined as overlooked stones by postoperative choledochoscopy.(ABSTRACT TRUNCATED AT 400 WORDS)