Extracorporeal Shock Wave Lithotripsy

The kidneys and the Urinary system

The main purpose of the kidneys is to filter metabolic wastes, excess ions, chemicals and water from the blood in the form of urine.

The kidneys, ureters, urinary bladder, and urethra together form the urinary tract, which allows the urinary system to drain urine from the kidneys and temporarily store it in the bladder before expelling it from the body during urination.

Besides filtering and eliminating wastes from the body, the urinary system also helps maintain the homeostasis of water, ions, pH, blood pressure, calcium and red blood cells.

The kidneys are situated at the back of the torso under the ribcage at around the level of the eleventh and twelfth rib, one on each side. An adult kidney is generally about the size of a fist.

Each kidney has an outer layer called the cortex, which contains filtering units. The centre part of the kidney, the medulla, has fan-shaped structures called pyramids. These drain urine into cup-shaped tubes called calyces and it is in these calyces where kidney stones are usually formed.

Kidney Stone Formation

Sometimes the kidney filtering system is unable to completely filter out the waste products and small particles of waste clump together to form lumps of solid crystals and salts.

These are known as kidney stones but are also referred to as renal calculi and can block the flow of urine and cause infection, kidney damage or even kidney failure. They can vary in size from a few millimeters upwards and can occur anywhere in the collecting system of the kidney.

The risk of getting a kidney stone is about 1 in 10 for men and one in 20 for women and at any one time in Australia, it is estimated that between 6 and 8 percent of the population may be suffering with kidney stones.
Lithotripsy, using shockwaves, is the choice of many as it is a safe, non-invasive treatment option.