Abstract
An article that advocates the use of extracorporeal shockwave lithotripsy (SWL) in the treatment of ureteral stones and shows the excellent results to support it. How refreshing.
Stone surface area instead of the longest diameter is used to describe the stone burden. This is much more precise. Ideally a stone volume would be used, but this is not easily done in daily practice. Stone surface area already gives a better idea of stone burden and should perhaps be commonly used when reporting on stone treatment.
Shockwaves were administered at a fast rate of 120 shocks per minute. Although there is ample evidence that a slower rate improves outcome and diminishes the incidence of adverse tissue effects in kidney stones, there is no literature on this in the treatment of ureteral stones.
However, with a faster shockwave rate residual cavitation bubbles generated by the previous shockwave may not fully be resolved. This way the amount of cavitation bubbles increases with each shock and the persisting bubbles can block the subsequent shockwaves rendering them less effective. This purely physical effect occurs regardless of stone location.
The effects of cavitation on tissue, in contrast, are more visible and more deleterious if there is more liquid in the tissue. Hence the possible adverse effects will be more obvious in the kidney than the ureter.
If not to prevent adverse effects a slower shockwave rate, therefore, could still have an advantageous effect on the fragmentation of ureteral stones.
Finally the authors with good reason conclude that SWL is still an effective modality in the management of distal ureteral stones. Apart from being effective, complications of SWL are virtually nonexistent in the distal ureter and, because of its minimally invasive nature, SWL remains the obvious preference of patients.