Extracorporeal shock wave lithotripsy in symptomatic cholesterol gallbladder stone patients with a second generation electrohydraulic lithotripter (MPL-9000): experiences with 106 patients over 15 months.

One hundred and six patients were treated with a second generation underwater spark discharge lithotripter (Dornier MPL-9000). During the 15-month study period, Kaplan-Meier analysis predicted a stone clearance rate of 16.5% after 4 months, 37% (7 months), 71% (10 months), and 81% (15 months), respectively. Patients with multiple stones had a 5% probability to be free of stones after 13 months of treatment, when compared to 100% in patients with solitary stones smaller than 2 cm (p less than 0.001). Stones with densities below 100 Hounsfield units (HU) on computed tomography disappeared in 75% of the cases within 13 months. Rim calcified stones were cleared in 100% after 10 months of treatment. Fragmentation efficacy proved to be an essential predictive parameter for stone clearance: a fragment size below 5 mm after extracorporeal shock wave lithotripsy resulted in a 100% stone clearance within 13 months regardless of the initial stone number, size, and density. None of the stones fragmented to pieces of more than 10 mm in diameter could be dissolved within the observation period. Obviously, modern generation electrohydraulic lithotripters are effective in stone fragmentation, thus providing the basis for successful bile acid therapy provided the patients are properly selected.