Kidney stone erosion by hydrodynamic cavitation and consequent kidney stone treatment

Official URL: http://dx.doi.org/10.1007/s10439-012-0559-7

The objective of this study is to reveal the potential of micro scale hydrodynamic bubbly cavitation for the use of kidney stone treatment. Hydrodynamically generated cavitating bubbles were targeted to the surfaces of 18 kidney stone samples made of calcium oxalate. Their destructive effects have been exploited in order to remove kidney stones in in vitro experiments. Phosphate buffered saline (PBS) solution was used as the working fluid under bubbly cavitating conditions and under 9790 kPa pressure in 0.75 cm long micro probe of 147 *m inner diameter. The surface of calcium oxalate type kidney stones were exposed to bubbly cavitation at room temperature for 5 to 30mins with 5 minutes time intervals. The eroded kidney stones have been visually analyzed with a high frame speed CCD camera and using SEM techniques, and their masses have been compared at specific time intervals. The results showed that at a cavitation number of 0.017, hydrodynamic bubbly cavitation device could successfully erode stones with an erosion rate of 0.31mg/min. It has been also observed that the targeted application of the erosion with micro scale hydrodynamic cavitation may even cause the fracture of the kidney stones within a short time of 30 minutes. The proposed treatment method has proven to be an efficient instrument for the destruction kidney stones. Therefore, this method might be considered as a strong alternative to widely used techniques such as ultrasound therapy.