Fig. 3 59 years old, male. A case of common bile duct stone. Endoscopic picture shows that an ellipsoid stone exists in the common bile duct. Fig. 1 77 years old, female. A case of common bile duct stone. 7 Fr PTCD tube is inserted into the common bile duct. Cholangiogram shows that there is a smooth round shaped filling defect in the common bile duct. Fig. 4 Same case as Fig. 3. Endoscopic picture of the end of the common bile duct shows that no stone remains after removal of stones. Fig. 2 79 years old, female. A case of retained common bile duct stone. After fistula is dilatated using Ichikawa's method, 16 Fr PTCD tube is inserted into the common bile duct. Cholangio gramshows that there is an ellipsoid filling defect in the common bile duct. (94)

Fig. 5 Same case as Fig. 1. X-ray shows that biopsy of the end of the common bile duct is performed endoscopically using cholangiofibers - cope. Table 1 Duration of PTCD, number of EHL occurrencies. EHL=Endoscopic electrohydraulic lithotripsy (mean }SD) Table 2 Relationship between location of stones and composition of stones. (95)

Table 3 Effects of treating for pain: Use of nitrous oxide pentazocin and diazepam. Pain Intensity Score (by Momose)III. High: Intolerable pain, we need to administrate an analgetic. II. Medium: A patient desires administrating of an analgetic but we ask the patient to tolerate the pain if possible. I. Low: Upon asking the patient whether he/she feels any pain or not, his/her answer is affirmative. 0 Nothing: No pain. N2O: Nitrous oxide (96)

Table 4 Period of admission and period of therapy comparison between EHL and operation. Period of therapy (EHL): Period from PTCD until discharge. Period of therapy (Operation): Period from Operation until discharge * p<0.01 (mean }SD) Table 5 Period of admission comparison between cases of jaundice and no jaundice. No jaundice: Cases whose number of total bilirubin was below 2mg/dl Jaundice: Cases whose number of total bilirubin was over 2mg/dl (97)

13) Koch H, Stolte M, Waltz V: Endoscopic lith otripsyin the common bile duct. Endoscopy 1977, 9: 95-98 14) Koch H, Rosch H, Walz V: Endoscopic lith otripsyin the common bile duct. Gastrointesti alendoscopy 1980, 26: 16-18

18) Lear JL, Ring EA, Macoviak JA, et al: Per cutaneoustranshepatic electrohydraulic lith otripsy.radiology 1984, 150: 589-590 19) Burhenne HJ: Complicatins of nonoperative extraction of retained common duct stones. Am J Surg 1976, 131: 260-262 20) Amberg JR, Chun G: Transcystic duct treat mentof common bile duct stones. Gastrointest Radiol 1981, 6: 361-362 21) Hwang MH, Lee HH, Lin J, et al: Trans cholecysticendoscopic Endoscopy 1987, 19: 24-27 choledocolithotripsy. The clinical study on the utility of endoscopic electrohydraulic lithotripsy of common bile duct stone Tamaki YAMADA, Toshiyuki SUZUKI, Eiji KOBAYASHI, Keiichi MORITA, Nobuo YOSHIOKA, Yutaka OGAWA, Tomoyuki KUMAI, Hiroshi ISHIGURO and Sadasuke SUZUKI Department of Internal Medicine, Kariya General Hospital Using the cholangiofiberscope, electrohydraulic lithotripsy was performed in 20 patients with biliary tract stones. In all cases, stones were destroyed and removed without any serious complications. Since these treatments no recurrence of stones has been recognized (average 8.6 months, longest 16 months). The average period of PTCD needed for the treatments was 34.3 }8.1 days, and the average number of treatments needed was 1.7 }1.0. The average time taken was 91 }26 minutes, and the peroid from PTCD until hospital discharge was 39.8 }6.1 days for cases of common bile duct stone, and 46.3 }8.8 days for common bile duct and gall bladder stone. This period for cases of common bile duct stone is equivalent to that taken by surgical procedures in our hospital. This treatment seems to be at least as good as EST or surgery for cases of common bile duct stone. It is especially appropriate for those patients who reject surgery, are elderly, poor risks, or recurrent cases. (100)