[Compression of extracorporeal lithofragmentation based on the petrographic structure of the calculus]

A total of 114 calculi with 6 different compositions: whewellite (OXMH), whedellite (OXDH), struvite (FAM), carbopatite (CA) uric acid (UA) and oxolophosphate (OP) have been fragmented in vitro using 2 extracorporeal (electrohydraulic and piezoelectric) and 2 direct contact (ultrasound and laser) sources. A petrographic study of the calculi following their inclusion in acrylic thermoplastic resin allowed the definition of the different crystallographic patterns of each composition. Fragmentability and fragmentation spectra based on the particle size of each lithiasic composition are justified by the petrographic structure of the calculi. The intercrystalline cleavage charts explain fragmentability, while fracture lines in the crystal core the crushing susceptibility. The lithiasic fragility lies in the crystal's intercrystalline and intermolecular linking energies.