[Comparative analysis of lithiasic fragmentation induced by extracorporeal and direct contact sources].

An in vitro experimental study on stone fragmentation was conducted on 114 calculi analyzed by infrared spectrophotometry. Four energy sources were utilized: electrohydraulic, piezoelectric, ultrasound and pulsed laser. We analyzed stone susceptibility to fragmentation (particles < 3 mm), pulverization (particles < 1 mm) and stone fragility (amount of energy/mg of calculus fragmented into particles < 3 mm) for each type of energy source of each of the following 6 stone compositions: calcium oxalate monohydrate, calcium oxalate dihydrate, magnesium ammonium phosphate, phosphate carbonate, uric acid and phosphate oxalate. The calcium oxalate dihydrate calculi were the most susceptible to fragmentation and the infective calculi (magnesium ammonium phosphate and phosphate carbonate) were the most susceptible to pulverization. The piezoelectric energy showed the highest capacity for fragmentation and pulverization of calculi. Stone fragility depended on each stone type and the energy source utilized.