[Extracorporeal lithotripsy in experimental vesicular lithiasis in pigs].

Experimental extracorporeal shock wave lithotripsy of gallstones was performed with the EDAP LT 01 piezoelectric lithotripter. Fragmentation of biliary stones was evaluated after implantation of human stones inside the gallbladder in 10 pigs. Lithotripsy was performed with a firing frequency of 2.5 shots per second during a mean time of 50 min. Zero to 18 days after lithotripsy, complete fragment clearance was seen in 6 cases, fragments less than 2 mm were found in 2 cases and fragments larger than 2 mm with only 1 non fragmented stone in 2 cases. There were no stone fragments in the cystic and common ducts. Damage to gallbladder and adjacent organs was appreciated after lithotripsy to the empty gallbladder of pigs with firing frequencies from 40 to 1.25 shots per second. Perforation of the gallbladder was observed in both pigs treated with a firing frequency of 40 shots per second and in 1 pig out of 3 treated with a firing frequency of 20 shots per second. With 10 shots per second and lower firing frequencies, mild histological changes of the gallbladder walls were only observed in 3 cases reoperated on the 2nd day after lithotripsy. The gallbladder wall was normal in the 5 cases reoperated on the 15th day and there were no hepatic, duodenal and pancreatic lesions. These experimental results are consistent with utilization of this machine in the treatment of gallstones in man; low firing frequencies are effective for fragmentation of gallstones without any adverse effects.