Wolf Piezolith 2200 versus the modified Dornier HM3. Efficacy and range of indications.

From February to September 1987, a prospective study was performed at two clinics to compare the Piezolith and the Dornier HM3+ lithotripters. Based on the same clinical indications for extracorporeal shock wave lithotripsy, 334 patients were treated with the Dornier HM3+ and 378 patients with the Piezolith. Whereas stone size was similar in both groups, more ureteral calculi were treated with the Dornier HM3+ (31.1 versus 23%). The rate of successful disintegration and total number of auxiliary measures were similar in both groups. However, the mean number of impulses (HM3+ 1,997 versus Piezolith 2,855) and number of secondary ESWL treatments (HM3+ 15.5% versus Piezolith 45%) differed significantly. According to the locating systems, the success of in situ treatment was similar for renal calculi; however, fewer ureteric stones could be treated in situ at the Piezolith (HM3+ upper ureter 70.6%, middle ureter 82%, distal ureter 71.4% versus Piezolith upper ureter 37.5%, middle ureter 0%, distal ureter 62.8%). The stone-free rate at discharge and after 3 months did not differ in both centers (HM3+ 75% versus Piezolith 72%).