Optimized extracorporeal shock wave lithotripsy of gallbladder stones: A prospective, randomized comparison

Is "pulverization" or fragmentation the best endpoint of extracorporeal shock wave application in ESWL of gallbladder stones? Has gallbladder motility a potential for the prevention of stone recurrence? Methods: Prospective, monocentric study with randomization between the conventional treatment strategy (endpoint of shock wave application: fragments less than or equal to 4 mm, concomitant oral chemolitholysis) and an intensified treatment strategy (endpoint of shock wave application: Pulverization, no chemolitholysis). Prevention of stone recurrence:;lt least once per month for one hour after a meal standardized position (back position, lowered chest). Results: 34 patients, age 46 +/- 14 years (27 women, seven men) were included (F-ESWL: n = 18; P-ESWL: n = 16). Gallbladder motility, number, size and CT-measured calcifications of stones were comparable for both groups. P-ESWL patients received more shock wave pulses than F-ESWL patients and more treatment sessions. P-ESWL resulted in a better fragmentation and pulverization of stones was reached significantly more often (p < 0.05). The time period for stone clearance was significantly depending on the fragmentation result (pulverization: 0.7 months vs. fragments less than or equal to 4 mm: 6.6 months vs. fragments > 4 mm: 8.0 months; p < 0.01). The stone free rate after twelve months was 87.5 % for P-ESWL and 72.2 % for F-ESWL (n. s.) and correlated significantly with the fragmentation result (p < 0.01). Pain sensations during stone clearance were significantly reduced by P-ESWL. Stonefree patients were followed up for 30 +/- 13 months, the total recurrence rate was 7.1 %. Conclusions: Aiming for pulverization of gallbladder stones by means of intensified extracorporeal shock wave application is at least equal or in tendency superior compared to disintegration to fragements less than or equal to 4 mm. Gallbladder motility might be useful to prevent gallstone recurrence after successful ESWL.