Efficacy of second generation lithotriptors: a multicenter comparative study of 2,206 extracorporeal shock wave lithotripsy treatments with the Siemens Lithostar, Dornier HM4, Wolf Piezolith 2300, Direx Tripter X-1 and Breakstone lithotriptors.

Extracorporeal shock wave lithotripsy (ESWL) has become the treatment of choice for urinary calculi. The good results of the first generation Dornier HM3 lithotriptor stimulated the development of second generation machines. A multicenter trial is presented involving the Siemens Lithostar, Dornier HM4, Wolf Piezolith 2300, Direx Tripter X-1 and Breakstone lithotriptor to compare the therapeutic efficacy of second generation machines. Treatment results were best for calculi less than 2 cm. in diameter. Although the second generation lithotriptors are comparable to each other, none of the machines provided a success rate comparable to that of the first generation unmodified Dornier HM3 lithotriptor. The 5 machines differed mainly in types of stones treated in relation to imaging system, use of anesthesia, use of auxiliary procedures and hospitalization but overall success rates were similar. We conclude that second generation ESWL is less effective than first generation ESWL.