Broad-Beam Ultrasound for Acceleration of Struvite Calculi Dissolution Using Citric Acid-Based Chemolytic Agents

A computer-controlled broad-beam ultrasound system is presented that accelerates struvite stone chemolysis in vitro. Hemiacidrin chemolysis was greatly potentiated and was linearly dependent on stone surface area and total ultrasound time. Dissolution also was dependent on citric acid concentration and solution pH, with only minimal dissolution above pH 4.2. Citrate concentrations of 12% provided maximal dissolution that was further potentiated by 0.1 M EDTA. With or without ultrasound application, the citrate-based compound demonstrated eight-fold greater activity than hemiacidrin. Magnesium competitively inhibited dissolution.