Definition of Extracorporeal shock wave lithotripsy

Extracorporeal shock wave lithotripsy: A technique for shattering stones such as kidney stones or gallstones with a shock wave produced outside the body.

To focus on kidney stones here, there are several methods available for producing an acoustical or ultrasonic "big bang" which can be focused from outside onto the kidney and the kidney stone. The stone breaks up after 800 to 2000 shocks. Lithotripsy results are generally good with kidney stones that are less than 1.5 cm (5/8th of an inch) in diameter.

The lithotriptor (the stone crushing machine) used to crush kidney stones is operated by a urologist. Anesthesia may be necessary to control the pain, depending on the size and density of the stone and the energy of the shock wave needed to break it up. The urologist may opt to place a catheter (stent) in the ureter (the tube running from the bladder to the outside) from below to facilitate passage of the shattered fragments.

The first use of shock wave lithotripsy to destroy kidney stones in people was in 1980. Within a few years, it became the standard treatment for renal stones. Shock wave lithotripsy of gallstones began in 1985. Although it worked well in patients with a single small stone, the method did not gain wide acceptance because of difficulty in clearing the fragments and the tendency to new stone formation. Treatment of stones in the common bile duct, pancreatic duct, and salivary gland has gained general acceptance. Extracorporeal shock wave lithotripsy is also known as ESWL© (Dornier Medical Systems, Inc.).