Extracorporeal Shock Wave Lithotripsy (ESWL)

Extracorporeal Shock Wave Lithotripsy (ESWL) is the non-invasive treatment of kidney stones (urinary calculosis) and biliary calculi (stones in the gallbladder or in the liver) using an acoustic pulse. The lithotriptor attempts to break up the stone with minimal collateral damage by using an externally-applied, focused, high-intensity acoustic pulse. An overview of the procedure is as follows:

• You lie on a water-filled cushion, and the surgeon uses X-rays or ultrasound tests to precisely locate the stone. High-energy sound waves pass through your body without injuring it and break the stone into small pieces. These small pieces move through the urinary tract and out of the body more easily than a large stone.
• The patient may receive sedatives or local anesthesia.
• Your surgeon may use a stent (a small, short tube of flexible plastic mesh that holds the ureter open) when your stones are larger than 2.5 cm. This helps the small stone pieces to pass without blocking the ureter.
• ESWL is an outpatient procedure. After the procedure it may take a few days for all the stone fragments to pass from your body. The treatment usually starts at the equipment's lowest power level, with a long gap between pulses, in order to accustom the patient to the sensation. The frequency of pulses and the power level are then gradually increased to break up the stone more effectively.