Burst wave lithotripsy – the new evolution stage of extracorporeal shock-wave lithotripsy

Urolithiasis is currently one of the most urgent problems in the world. Every eleventh worldwide inhabitant suffers from this disease. Previously, the only way to get rid of kidney stones and the urinary tract was open surgery, which was characterized by high trauma. Over the past decades, the development of technologies has made a significant contribution to the development of new methods of urolithiasis treatment. One of these methods is extracorporeal shock wave lithotripsy (ESWL). The first lithotripter Dornier HM-1 was produced in 1980. Subsequent models have got many changes, both in terms of ergonomics and power. The researchers noticed that the efficiency of stone crushing in the Dornier HM-1 lithotripter was higher than in newer models since the lower power provided the less intensive formation of cavitation bubbles that prevent the effective transit of subsequent waves through the stone. Nowadays, a new method of remote stone crushing is being developed based on low-amplitude high-frequency technology combined with ultrasonic propulsion, which is the main difference from traditional shock-wave lithotripters. The new technology of stone crushing is called «burst wave lithotripsy» (BWL). Currently, the data have been obtained that this method is more effective in terms of crushing quality and less traumatic.

Shock Wave Lithotripters With Broad Focus Result in Greater Stress in Human Kidney Stones: Numerical Simulation

Shock wave lithotripsy (SWL) has been used to treat kidney stones for decades. However, there is growing recognition that shock waves induces trauma to kidney tissue [1, 2]. The poor understanding of stone comminution mechanisms means that the design of new lithotripters is principally a practice of empiricism [3]. A mechanistic understanding of stone comminution would provide a criterion to develop new lithotripsy systems. In this work, a three-dimensional finite-difference time-domain (FDTD) solution to the linear elastic equations was employed [4] to investigate the stress and displacement fields of kidney stones subject to lithotripsy shock waves. The kidney stone models were obtained from micro-computed tomography images (resolution of 20 μm) and have diameters from 2 mm to 5 mm.