Increased gallbladder residual volume in nonresponders to extracorporeal shock wave lithotripsy of gallbladder stones.

In a prospective study of 63 patients, we purposed to determine whether gallbladder contractility or gallbladder volume before biliary lithotripsy are predictors of fragment disappearance. Percentage gallbladder contraction was calculated from the fractional difference in the sonographically measured gallbladder volume after a standard fatty meal. Statistical analysis showed no significant differences in gallbladder contractility between the fragment-free group and the residual-fragment group before (77.2 +/- 12.7% vs. 71.9 +/- 19.3%; p = 0.1044) biliary lithotripsy and after the termination of adjuvant cholelitholysis therapy (76.4 +/- 12.9% vs. 72.2 +/- 17.1%; p = 0.1341). Before treatment, there was no significant difference in fasting gallbladder volume in either group (29.9 +/- 15.4 ml vs. 36.6 +/- 18.8; p = 0.0682), but postprandial gallbladder volume was greater in nonresponders (10.4 +/- 9.4 ml vs. 6.5 +/- 3.8; p = 0.0164). After termination of the therapy, both the fasting gallbladder volume (41.2 +/- 24.2 ml vs. 29.8 +/- 10.3 ml; p = 0.0093) and the postprandial gallbladder volume (11.9 +/- 11.7 ml vs. 7.3 +/- 5.3 ml; p = 0.0267) were greater in the residual-fragment group. The increase of the fasting gallbladder volume in the residual-fragment group was statistically not significant. Our results indicate that the increased residual volume is a significant cause of therapeutic failure in nonresponders.