Extracorporeal shock wave lithotripsy of gallstones in different biles and water in vitro

Twenty-four gallstones were fragmented by extracorporeal shock wave lithotripsy (ESWL) to compare the influence of three different biles (bovine bile, human bile, synthetic bile) and water on the rapidity of fragmentation. Four groups of comparable stones were used for lithotripsy in vitro. The stones were collected from 6 patients, four nearly identical 'sister' stones from each patient. The number of shock waves required for adequate fragmentation (fragments < or = 4 mm) was measured for comparison. Overall highly significant differences were found for the four different 'biles' with regard to the number of shock waves required for adequate fragmentation. Using synthetic bile, which was artificially composed according to a textbook on hepatology, significantly more shock waves were necessary for fragmentation compared to the use of water, bovine bile or human bile. On the other hand, no significant difference between water and human bile could be registered. We conclude that the number of shock waves required for adequate lithotripsy is influenced by the composition of bile in which the stone is fragmented. Possibly results of ESWL can be improved by manipulation of the bile.