Comparison of efficacy of German and Chinese electromagnetic shock wave lithotripters: Dornier Compact S vs Huikang MZ-SWL-V

Objectives To compare the treatment efficacy of Dornier Compact S and a Chinese electromagnetic shock wave lithotripter (Huikang MZ-SWL-V) in a large series. Methods We retrospectively reviewed the outcome of shock wave lithotripsy (SWL) in 13,954 consecutive patients with upper urinary tract stones from December 1996 to December 2008 with Dornier Compact S (9124 cases) and Huikang MZ-SWL-V (4830 cases). An intramuscular injection of 50 mg pethidine was given to the patients with Dornier Compact S but not to those with Huikang MZ-SWL-V. Treatment outcomes were assessed by the stone-free rate at three months, the retreatment rate, the auxiliary procedure rate, and the effectiveness quotient. The pain scores were evaluated by visual analog scales, where 0 = pain and 10 = unbearable pain. Results The overall stone-free rate at 3 months, retreatment rate, and ancillary procedure rate for Dornier Compact S were 95.9%, 13.4%, and 2.2%, respectively, and they were 85%, 29.6%, and 10.2%, respectively, for Huikang MZ-SWL-V. The overall efficiency quotients of Dornier Compact S and Huikang MZ-SWL-V were 83% and 60.8%, respectively. However, the pain scores in the Dornier group (6-10) were higher than those in the Huikang group (1-5). Three clinically significant subcapsular hematomas were detected in the Dornier group but there were none in the Huikang group. Conclusions Dornier Compact S is more effective than Huikang MZ-SWL-V, but SWL with Huikang machine could be performed with milder pain and without analgesia, and a lower significant hematoma rate was observed in Huikang group.