Kidney Stones - Prevention

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Devices Used to Destroy Stones. For large stones, some type of energy-delivering device may be needed to break the stone into small pieces. These are referred to as intracorporeal lithotripsy devices (meaning stone breakers within the body), and may include:

• Ultrasound is currently the preferred method. It results in a stone-free rate of more than 90%. A rigid nephroscope delivers the ultrasound waves.
• Pneumatic (compressed air) lithotripsy uses a probe that comes in direct contact with a stone. Compressed air causes a piston to collide rapidly with the probe, and the result is a "jackhammer" action that breaks up the stone. However, this method can send stone fragments into other parts of the urinary tract.
• A more recent device uses a combination pneumatic probe and ultrasound. It produces stone-free rates of over 80%. It may prove to be superior to ultrasound alone, and it is effective against stones of all types.
• The holmium laser uses a flexible nephroscope to literally melt the stones. This laser destroys up to 100% of all types of stones and it has an excellent safety record. It should be used sparingly, however, and with particular caution on large uric acid stones until more is understood about its effect. (Another device, the erbium: YAG laser shows promise for lithotripsy, but is not currently in clinical use.)

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Complications. Complication rates are about 3%. Major complications occur in about 1% of patients. Scarring of the tissue is one possible complication, but studies indicate that this scarring does not impair kidney function, even if the patient needs to have repeat surgery. There is also a risk for blood loss during and after the procedure, which sometimes can be significant.

Because the procedure uses large volumes of fluid, fluid overload is a potential problem, particularly in children or patients with heart disease.

Infection may result in some patients. Other complications may include a collapsed lung and injuries to areas outside the kidney (but within the operative area), such as the abdomen or chest.