Use of external shock-wave lithotripsy and adjuvant ursodiol for treatment of radiolucent gallstones. A national multicenter study.

A prospective multicenter trial was performed to evaluate the use of external shockwave lithotripsy (ESL) and adjuvant medical therapy for the treatment of gallstones. A Medstone STS lithotripter was used together with ursodiol. Two hundred twenty-three patients were treated under general anesthesia (75%) or with intravenous analgesia (25%). Initial treatments were on an inpatient basis, but as centers gained experience, outpatient treatments became more common. Stone fragmentation and clearance were greatest in patients with solitary gallstones less than 2 cm in diameter. In this group of patients, stone fragmentation occurred in 97% of patients, and the cumulative stone-free rates at three and six months were 54% and 90%, respectively. These results indicate that fragmentation of gallstones can be achieved by a dry shock-wave lithotripter and that stone clearance is induced more rapidly by external shock-wave lithotripsy and adjuvant ursodiol therapy than by ursodiol therapy alone.