[Tissue effects of extracorporeal lithotripsy on a model of experimental biliary calculi in dogs]

Extracorporeal shock waves represent a new method to treat gallstones. This study was designed to evaluate: 1) the effectiveness of a recently available lithotripter (EDAP LT 01) for gallstone fragmentation; 2) adverse tissue reactions after treatment; 3) the optimum conditions for use of this apparatus in man. A human cholesterol stone was surgically implanted into the gallbladder of ten 20-25 kg mongrel dogs. One dog was used as a control. The other nine animals were divided into three groups (A, B and C). Two 60 min sessions of lithotripsy were carried out twice a week. Sonographic and CT examinations were performed 9 and 16 days after operation. The animals were killed 21 days after operation. Satisfactory fragmentation was obtained in 4 of the 9 animals, and in 2 dogs no stone fragments were detected. Fragments were found in the common bile duct in 5 dogs. In 2 animals a pathologic aspect of the papilla of Vater was observed. Marked hematoma was observed in the animals treated at 5 and 10 pulses/sec. In 5 cases, hematoma was observed in the gallbladder and in one case the gallbladder was ruptured. Hematoma was also noted in the hepatic vascular bed in 3 animals. Except for microscopic hemorrhagic lesions observed at the base of the right lung, no lesions were detected in any other organ. Shock waves produced by the EDAP LT 01 are effective for fragmentation of gallstones. However, in view of the tissue reactions observed at the higher pulse rates, the pulse rate should not exceed 2.5 pulses/s for use in man.