Health Topics: Kidney Stones

What are they?

Kidney stones are crystals that form in the kidneys or small tubes that drain the urine from the kidney to the bladder. These tubes are called the ureters. The stones are often composed of salts and of calcium, but can be formed of other substances including uric acid and cystine.

Who gets them?

Kidney stones are more common in men than in women usually beginning in the 40's or 50's. They are also more common in Caucasians than in African Americans.

There are numerous reasons why people can form kidney stones. The most common reason is a failure to drink adequate amounts of fluids. Stones are more common in the warm weather months and in warm weather climates because people generally are more dehydrated due to excess fluid losses secondary to sweating. Other factors can contribute to stone formation including certain dietary excesses. As a general rule, it is fine for most people that form stones to drink milk and to eat other products that contain calcium. Patients who form kidney stones should not avoid calcium products unless specifically advised by their doctor.

Certain patients have metabolic disorders that lead to the formation of kidney stones. These disorders can usually be identified using a combination of blood and urine tests. In addition, certain stones are caused by infection with specific types of bacteria. Again, your doctor can identify if you are at risk for forming these types of stones.

What are the typical symptoms of kidney stones?

1. Pain. The pain is usually felt in the back on one side or the other. The pain will sometimes radiate around into the front of the abdomen down towards the groin region. Then the pain can sometimes be felt in the testicle or scrotum in men and in the vaginal area in women. Many patients with kidney stones will pass visible blood in their urine. Often times, however, the blood is only microscopic and thus it would require a laboratory test to show its presence. There are many other causes of blood in the urine besides kidney stones. We recommend that anyone with blood in the urine be evaluated by a physician.

2. Other symptoms. Symptoms of kidney stones can include nausea and vomiting. This is usually associated with the back or side pain. The pain typically comes and goes, meaning that it will start out relatively mild and become quite severe and then decrease in severity again. Sometimes in between attacks the pain will disappear completely. Other symptoms can include fever, particularly if the stone is blocking the flow of urine from the kidney and there is infection present. Frequency of urination or discomfort with urination can also be a symptom of kidney stones.

What are the treatment options?

1. Watchful waiting
   Most stones that patients form will pass on their own. It is usually recommended that patients consume large amounts of fluids, at least two quarts per day. Water is recommended as the primary fluid. If patients are on any type of fluid restriction because of heart problems or high blood pressure, they certainly should consult with their physician before substantially increasing their fluid intake. With adequate fluid intake, more than 70% of stones will pass spontaneously. Oral pain medications usually are necessary. It is recommended that you contact your physician if you think that you may be experiencing a kidney stone. The most important criteria to determine if a stone will pass is the size of the stone. This can be determined most accurately by x-ray studies including an IVP, CT scan or ultrasound.

2. Extra corporeal Shock Wave Lithotripsy (ESWL)
   ESWL is a noninvasive treatment for kidney stones. It involves using shock waves that travel through the skin and are focused on the kidney stone. The shock waves cause the stones to break up into small pieces that are then passed by the patient. The older ESWL machines involved placing the patient into a bathtub of water to aid in breaking up the stones. The newer machines, including the one here at Loyola, do not require placement of the patient into a tub of water. The primary advantage of ESWL is that it is noninvasive. It can usually be done with only intravenous sedation and does not always require general anesthesia. It is not always effective in large stones or stones in certain locations within the kidney. Also, some stones are simply too hard for ESWL and require a more invasive treatment.

3. Ureteroscopy
   Ureteroscopy involves passing a small telescope into the bladder via the urethra and then up the ureter tube to the kidney. It is primarily used for stones that are lodged in the ureter tube, but with the development of flexible instruments can now be done any where in the ureter tube or in the kidney. Through the small telescopes the urologist is able to pass small instruments such as a laser to disintegrate the stone or basket-like devices to remove the stone. This procedure usually requires either general or spinal anesthesia. Although it is more invasive than ESWL, it can have higher success rates, particularly when treating stones in the ureter tube.

4. Percutaneous Kidney Surgery
   Certain stones that are very large and exceed greater than one inch or those that fail to respond to the treatments listed above sometimes require a percutaneous treatment. This literally means through the skin, and involves passing a tube through the patient's back and directly into the kidney. This then allows passage of instruments directly into the kidney. These instruments can be used to fragment the stone into smaller pieces and then remove the fragments. This treatment is one of the more invasive treatments for kidney stones and is performed relatively infrequently compared to the other treatments.

5. Open Surgery
   On rare occasions open surgery is still recommended for kidney stones. This involves making an incision on the abdominal wall then freeing up either the kidney or the ureter tube, opening that area, and removing the stone. This is clearly the most invasive treatment for kidney stones and is seldom required with the advent of less invasive techniques.

If you have a kidney stone, or think that you might, you should see a urologist. He or she can then determine the proper evaluation and recommend the best treatment for your specific situation.

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