KIDNEY STONE GENERAL INFORMATION

What is a kidney stone?

A kidney stone is a rock or particle crystal in the urinary tract formed by substances in urine.

• Kidney stones affect 10% of men and 5% of women aged 30-50. Children and teenagers also get kidney stones.
  
   
• They vary in size from a grain of sand to the size of a tennis ball. Regardless of the size, they are one of the most painful medical problems known.
  
   
• Kidney stones can cause permanent damage to the kidneys if not treated appropriately.
  
   
• Recurrence is common. Men have a 67% recurrence rate.

What causes a kidney stone?

No one really knows. The most common theory is called supersaturation crystallization. In this theory, dehydration causes calcium phosphates, oxalates, urea, uric acids, citrates, complex mucoproteins or other trace elements in urine to combine and crystallize.

• Some studies show that dehydration increases the chances of having stones. Drinking plenty of water may prevent kidney stones. People living in the southeastern U.S. have more kidney stones than people living elsewhere, and it is thought that the cause may be related to temperature and dehydration.
  
   
• Studies have been conflicting on the relationship of minerals in water to kidney stones. Some studies show hard water (water with excessive calcium sulfate) contributes to kidney stone formation, while other studies show soft water (with excessive sodium carbonate) contributes to a greater incidence of stone disease. Yet other studies demonstrate that trace elements in water may be the culprit.
  
   
• A high fat diet seems to be related to kidney stones. Eating a high protein diet, dark green leafy vegetables, tea, and chocolate may increase the chance of forming kidney stones.
  
   
• Kidney stones tend to run in families.

Symptoms of a kidney stone

Kidney stones are very common and dangerous. If kidney stones are not treated properly, permanent kidney damage can result.

• A typical stone attack is a sudden pain occurring at night or in the early morning. The pain starts in the loin and radiates around the abdomen down into the groin.
  
   
• Nausea and vomiting are common. Often you cannot sit or lie still.
  
   
• Kidney stones are often confused with other diseases such as acute appendicitis, gastroenteritis, colitis and other bowel disorders. Occasionally those complaining of back pain for months, or even years, are found to have large kidney stones.

What to expect if a stone is suspected

• Because most kidney stones cause blood in the urine, the first test usually performed is a urinalysis and then a simple x-ray of the abdomen is taken to find the stone.
  
   
• An intravenous pyelogram (IVP)is often needed. In this procedure, a small amount of dye is injected through a vein, and x-rays are taken to find out exactly where the stone is and how big it is.
  
   
• Sometimes an ultrasound is used instead of an IVP, especially to avoid allergic dye reactions.
  
   
• In rare cases, a computed tomography (CAT) scan is necessary.
  
   
• If kidney stones begin to recur, a metabolic stone evaluation of urine and blood samples should be done to see if an underlying cause can be found.

Six different treatment options

1. Extracorporeal shock wave lithotripsy

Shock wave lithotripsy is often used to treat kidney stones. It is one of the most important technological advances in kidney stone treatment. It has a success rate of 98%.

All lithotripters are not alike. There is a new lithotripter that is dramatically better than others. Older machines use technology that's about 20 years old. They require a substantial amount of anesthesia, more x-rays, and a water bath. Not only does the new lithotripter allow you to skip the water bath, and probably the anesthesia, it treats more types of kidney stones (including those especially painful ones in the ureter) and can cut treatment time in half!

• In shock wave lithotripsy, a machine called a lithotripter is used to generate a shock wave outside of the body. The shock wave is focused on the kidney stone, which breaks into tiny pieces and passes painlessly. This is an outpatient procedure.
   
• The more advanced lithotripters do not require general anesthesia or water baths. In addition, they can treat stones in the ureter, avoiding ureteroscopy.

The Kidney Stone Center in Bloomington, Indiana, is one of the few places in the country that offers the new, advanced lithotripter, the Doli50 manufactured by the Dornier Corporation. Treatment by these new lithotripters is dramatically different than by the old types of machines. Be sure to find a new Doli50 lithotripter for your next kidney stone treatment.

2. Ureteroscopy

Used for stones in the lower ureter, this treatment has a 95% success rate.

• Ureteroscopy can be done as an outpatient procedure under anesthesia.
  
   
• A small telescope is passed through the bladder to the stone. The stone is removed using a small basket or is broken up using a very small shock wave probe.
  
   
• Following the procedure, a small silicone tube is left inside the ureter for 5-7 days to help relieve swelling.

3. Percutaneous nephrostolithotomy

If a kidney stone is larger than 3 centimeters (over 1 inch), a percutaneous nephrostolithotomy is often used for treatment.

• Instruments are passed through a small tract passing through the side of a patient into the kidney to break up the kidney stone.
  
   
• This procedure requires general anesthesia and hospitalization.

4. Electrohydraulic lithotriptor

This procedure uses shockwaves produced by a small internal probe to break up kidney stones.

• Commonly used for small kidney stones.
  
   
• Requires general anesthesia.

5. Open stone surgery

Rarely used anymore, this procedure requires a large incision and prolonged hospitalization.

6. Observation

Some kidney stones do not cause any pain. If small, they will pass on their own. Larger stones get stuck in narrow parts of the kidney and ureter, causing intense pain.

The best treatment for small, non-painful kidney stones usually is to allow them to pass on their own. An x-ray 1-2 weeks after discovery helps track how the stone is progressing.