The lessons from in vitro lithotripsy for the clinical treatment of gallstones.

Fifty-eight gallbladder stones were treated in vitro, using a Wolf Piezolith 2300 lithotripter, to discover whether complete fragmentation (i.e., no particles greater than 2 mm diameter) could be achieved by lithotripsy alone. In 16 stones this was accomplished with up to 6000 shocks being administered. The degree of fragmentation was judged first by eye during the experiment and then by both microscopy and sieving of the debris. Eye judgement proved to be an unreliable indicator with 23 of the 42 stones in the failed lithotripsy group receiving 6000 shocks or less. Cholesterol analysis and high resolution radiography revealed no significant differences between the successfully and unsuccessfully fragmented stones, but X-ray diffractometry did show a higher incidence of inorganic calcium salts in the latter group. This study shows that lithotripsy can successfully fragment gallbladder stones, but that a minimum of 6000 shocks, using the Piezolith 2300, should be given to ensure adequate treatment. Additionally, the presence of radiopaque stones does not necessarily preclude successful treatment by this method.