Extracorporeal shock wave lithotripsy (ESWL)
uses shock waves to break a kidney stone into small pieces that can more easily travel through the urinary tract and pass from the body.
ESWL works better with some stones than others. Stones that are smaller than 2 cm in diameter are the best size for ESWL. The treatment might not be effective in very large ones.
The sedated or anesthetized patient lies down in the apparatus bed, with the back supported by a water-filled coupling device placed at the level of kidneys. A fluoroscopic x-ray imaging system or an ultrasound imaging system is used to locate the stone and aim the treatment. The procedure uses ultrasound to generate shock waves that travel through the skin and body tissues until they hit the dense stones. Usually, the patient will be put to sleep with general anesthesia. The lithotripsy procedure takes about 45 minutes to one hour to perform. After lithotripsy, stone debris is removed from the kidney through urination.