Stone fragmentation pattern of piezoelectric shockwave lithotripsy in vitro

Whole stones (N = 64; largest diameter 5-15 mm) were treated in vitro with piezoelectric shockwaves using the Edap LT-01 lithotripter with 2.5 Hz at either 100% or 54% power. The number of fragments larger than 2 mm was counted after every 30 seconds. The stones were defined as totally broken when all fragments were < 2 mm. Total fragmentation time was correlated with the energy level and the size of the stone. The number of large fragments did not correlate with the energy level but rather with the original size of the stone.