How Are Kidney Stones Treated?

Kidney stones may be treated with:

• Extracorporeal shock wave lithotripsy (ESWL)

• Percutaneous nephrolithotripsy

• Laser lithotripsy

• Other methods

Extracorporeal Shock Wave Lithotripsy (ESWL)

ESWL focuses high-energy shock waves from a source outside the body and uses this energy to crush the stone into tiny pieces. These pieces are then small enough to pass out of the body during urination.

• Shock waves created by high-voltage discharges are focused on the kidney with the stone.

• The waves are transmitted through water. This is done either by placing the person's lower body in a tank of water or by positioning a water-filled cushion between the person and the source of shock waves.

• These shock waves do not damage the surrounding portions of the body.

• Most stones are reduced to a powdery substance following multiple shock-wave discharges.

ESWL is the treatment of choice under the following circumstances:

• People with just one stone, or those who have had ongoing problems with kidney stones, as long as the stones are no larger than three centimeters.

• People who may not be able to tolerate open surgery.

• People with certain health conditions, such as hypertension, breathing disorders, heart disease, and diabetes.

ESWL is most effective when treating stones smaller than three centimeters. It has best results when a stone is smaller than one centimeter in size and is located in the pelvic portion of the kidney. In these cases, the success rate is around 90 percent.

After ESWL, between 65 and 75 percent of individuals will no longer have kidney stones. The success rate is related to the size of the stone and the degree to which it can be crushed. If stone fragments remain in the urinary tract, there's a greater chance that new stones will form.

The effectiveness of ESWL also is related to the type of stone.

• Uric acid stones and certain types of calcium stones are easily eliminated through urination after they are crushed.

• Other types of calcium stones do not fragment easily and their stone-free success rate is only slightly more than 40 percent.

• Small cystine stones break up easily, but most large ones are difficult to shatter.

• When people with staghorn stones were treated with ESWL, the stone-free success rate at the end of six months was less than 50 percent, and over 60 percent of them needed to be treated again.

Problems can also occur when stone fragments remain after treatment, because of the likelihood that another stone will form.

Complications of treatment with ESWL may include blood in the urine and abdominal discomfort for several days. A severe cramping pain may occur as shattered stone fragments rub against the inside walls of the urinary tract on their way out of the body. However, the recovery time is fairly short.

Percutaneous Nephrolithotripsy

In this procedure, performed in an operating room after a person has been given anesthesia, a small incision is made in a person's flank. The surgeon guides a special scope to the kidney and punctures it. Using the pathway created, the surgeon inserts a small instrument into the kidney to break up the stone and remove the stone fragments.

This technique can be used to remove large stones and staghorn stones.

Laser Lithotripsy

With laser lithotripsy, a small instrument is inserted into the urethra and snaked into the ureter containing the stone. Focused laser energy is used to fragment the stone.

Other Methods

There are several other stone-removal techniques aside from lithotripsy. These procedures include percutaneous nephrolithotomy, uteroscopic stone removal, and open surgery.

• Percutaneous nephrolithotomy: The surgeon makes a small incision in the back and uses a special instrument to tunnel directly into the kidney. A nephroscope is then placed into the kidney and used to locate and remove the stone. Larger stones may require the use of ultrasonic or other forms of energy to fragment the stone into manageable pieces for removal.

The advantage of this procedure over lithotripsy is the physical removal of the stone fragments rather than relying on their natural passage from the kidney to the outside. This treatment is often used when the stone is large or in a location that does not permit the effective use of ESWL.

Uteroscopic stone removal: The surgeon passes a small fiber-optic instrument called a ureteroscope through the urethra and bladder and then into the ureter. The stone is then located and removed with the use of a special cage-like tool, or it is shattered with an instrument that produces a shock wave. A small tube called a stent is left in the ureter for several days to promote healing of this portion of the urinary tract. This technique is used when the kidney stone is located in the middle or lower portions of the ureter.

• Open surgery: In this procedure, performed in an operating room after a person has been given anesthesia, the surgeon makes an incision in the skin and opens the pelvis of the kidney or the ureter so that the stone can be manually removed. Because open surgery is a major operation, recovery may require four to six weeks.