What is Extracorporeal shock wave lithotripter?
        Extracorporeal shock wave lithotripter (ESWL) is a non-invasive treatment device of kidney stones (urinary calculus) using an acoustic pulse (extracorporeal shock wave) to break a large stone into smaller pieces that can pass
        Although calculus, especially calcium stones, are very hard, most of the 20% to 30% that do not pass out of the body on their own can be eliminated without surgery. The process called lithotripsy (from the Greek word for "stone crushing") breaks into tiny fragments most stones that are less than three-quarters of an inch across.
        Repeated shock waves cause the kidney stone to disintegrate into tiny particles. These particles pass easily out of the body in the urine.

History
        Lithotripsy and the lithotripter were developed in the early 1980s in Germany and came into widespread use in 1983. Within a few years, ESWL became a standard treatment of calculus.

How it works
        The lithotripter attempts to break up the stone with minimal collateral damage by using an externally-applied, focused, high-intensity acoustic pulse. The sedated or anesthetized patient lies down in the apparatus' bed, with the back supported by a water-filled coupling device. An imaging system is used to locate the stone and aim the treatment.
        The successive shock wave pressure pulses result in direct shearing forces, as well as cavitation bubbles surrounding the stone, which fragment the stones into smaller pieces that then can easily pass through the ureters. The process takes about an hour. A ureteral stent (a kind of expandable hollow tube) may be used at the discretion of the urologist. The stent allows for easier passage of the stone by relieving obstruction and through passive dilatation of the ureter.
        Extracorporeal lithotripsy works best with stones between 6 mm and 20 mm in diameter that are still located in the kidney and ureters.
        The patients undergoing this procedure can, in some cases, see for themselves the progress of their treatment. If allowed to view the monitor, they may be able to see their stones change from a distinct bright point (or dark spot depending on whether the fluoro unit is set up in native or bones white) to a fuzzy cloud as the stone is disintegrated into a fine powder.
        The passage of stone fragments may take a few days or a week and may cause mild pain. Patients may be instructed to drink as much water as practical during this time. Patients are also advised to void through a stone screen in order to capture stone fragments for analysis.

What are the advantages of Lithotripsy?
Lithotripsy offers many advantages over stone removal through surgery. Some of those advantages include:
1. Reduction in complications
2. Reduction in pain
3. Reduced recuperation time
4. Performed on outpatient basis 95% of the time
5. Able to resume normal activities much sooner
6. Reduced cost
7. No incision