To determine the effect of
chenodiol and
ursodiol pre-treatment prior to
shock wave
lithotripsy of
gallstones, two groups of 50 gallbladder stones (n = 100), obtained at
cholecystectomy, were matched according to their size, shape and weight. All stones were stored in a bile perfused gallbladder model for two weeks. In the first group (A), serving as control, native bile was used, whereas in the other group (B),
ursodiol- and
chenodiol-enriched bile was perfused, both
bile acids at therapeutic concentrations. After two weeks of pre-treatment, electromagnetic
shock wave
lithotripsy (19 kV, 1 Hz) was performed until stones were fragmented to a size smaller 2 mm. Neither stone density, as assessed by computed tomography, nor their
cholesterol content were different in group A and B. A trend towards higher fragmentation efficacy was observed for stones < 15 mm and for those with a CT-density < 100 HU. No influence of either stone shape (rounded vs. angular) or
cholesterol content was observed with regard to fragmentation efficacy. Comparing the number of
shock waves (SW) required for fragmentation (< 2 mm) there was no significant difference between group A (1850 +/- 1300 SW) and group B (1970 +/- 1500 SW, n.s.). These in vitro results do not support a significant role of
bile acids as a rationale pre-treatment prior to
lithotripsy of
gallstones.