Renal Complications of ESWL

Extracorporeal shock wave lithotripsy (ESWL), invented during the 1980s in Germany, uses concentrated pulses of sound waves to break up kidney stones too large to pass on their own into smaller pieces, which will then have a chance to be eliminated in the urine.  While this therapy has been an extremely useful and much less invasive tool for urologists to use in the treatment of kidney stones, there are nonetheless some side effects which nephrologists should be aware of.  

For instance, the trauma-induced by ESWL sound waves upon thin-walled vessels in the kidney can lead to microscopic hemorrhage, which later results in an influx of inflammatory cells and can potentially result in significant renal scar tissue if the exposure is great enough.  This would be most likely to occur in patients who have multiple rounds of ESWL for recurrent stones.  Interestingly, there is an emerging literature demonstrating that ESWL is associated with increased (though mild) diastolic hypertension, suggesting that this renal damage could be significant, and biomarkers of renal damage have been demonstrated to be elevated immediately post-ESWL.  In addition to these complications, there are others.  "Steinstrasse" is a German term (translated as "stone street") describing the post-ESWL accumulation of multiple small stone fragments, which may plug up the ureter and result in obstruction.  Hematuria, either gross or microscopic, is relatively common for a few days following the procedure.  Finally, bacterial sepsis and its resultant complications (due to translocation of bacteria in the bladder into the bloodstream during ESWL-induced damage to these tissues) can also result.