New generator for low pressure lithotripsy with the Dornier HM3: preliminary experience of 2 centers.

The technical innovation of a low pressure generator with a standard ellipsoid installed into the Dornier HM3 lithotriptor leads to a decrease in pressure at the second focus by 30 per cent. The preliminary experience with 273 patients treated at 2 centers is presented. The success rate in terms of stone disintegration was similar compared to the old generator (96 versus 97 per cent). However, the rate of secondary treatments increased from 8 to 15.5 per cent, respectively. Owing to the lower peak pressures at the second focus, an additional 700 impulses per session were necessary. The method of anesthesia was changed to a combination of an anxiolytic and analgesic drug in the majority of the patients. Treatment was judged as free of pain or with easily tolerable pain in 93 and 88 per cent of the patients, respectively.