Piezoelectric shockwave lithotripters : differences in fragmentation efficiency in vitro

In a comparative assessment of the stone fragmentation efficacy of different piezoelectric lithotripters 72 human gallstones consisting of 24 sets of 3 stones each were disintegrated in vitro using the Piezolith 2300, the EDAP LT.01, and the Therasonic. On the basis of the maximum diameter the calculi were divided into group A (6–15 mm; n = 3 × 16) and group B (16–25 mm; n = 3 × 8) and were treated by using the maximum energy setting of each lithotripter (Piezolith 2300: setting 4, high power; EDAP LT.01:95%; Therasonic: setting 7). Shockwave application was terminated when the residual fragments measured ≤4 mm or after a total number of 6000 pulses. With the Piezolith 2300 all calculi could be disintegrated into fragments ≤4 mm. In contrast, fragmentation was not successful, even after 6000 applied pulses, in the case of 2 and 6 stones when using EDAP LT.01 and the Therasonic lithotripters, respectively. With the remaining concrements of group A (n = 3 × 11) the fragmentation end point was achieved after...