New Treatment Options for Kidney Stones
by James E Lingeman, M.D. and Glenn M. Preminger, M.D.
James E. Lingeman, M.D. is a clinical professor in the Department of Urology at the Indiana University School of Medicine and the Director of the Methodist Hospital at The Institute of Kidney Stone Diseases. Dr. Lingeman is a member of the A.F.U.D. Kidney Health Council.
Glenn M. Preminger, M.D. is a Professor of Urologic Surgery, Director of the Comprehensive Kidney Stone Center and Director, Urology Residency program at the Duke University Medical Center. Dr. Preminger is a member of the A. F.U.D. Kidney Health Council.
Kidney stones are formed by various crystals that gather in your kidneys or urinary tract. These materials build up over a period of time and ultimately interfere with urination. Stones can be anywhere from gravel or pebble-sized to several inches in diameter. Kidney infections can create much larger or "staghorn" kidney stones.
Extracorporeal Shock Wave Lithotripsy (ESWL) has been used in the United States since 1984, and many different types of lithotripsy machines are currently in use. Over 90 percent of patients who are selected for treatment will have satisfactory pulverization of their stones with lithotripsy.
Approximately 50-80 percent of patients treated with lithotripsy become stone-free, depending on the size and type of stone treated. Most of the remaining patients pass the majority of their stone(s) but are left with some residual stone fragments that cause no symptoms. About ten percent of patients undergoing lithotripsy will require further therapy (usually ureteroscopy or percutaneous lithotripsy) to successfully treat their stone(s).
About 10-30 percent of patients will require more than one lithotripsy treatment to completely pulverize their stone(s). These cases generally involve the treatment of multiple stones or large stones. In conjunction with the lithotripsy treatment, it is occasionally necessary to use a ureteral stent. A stent is a soft plastic tube placed inside the urinary tract, extending from the kidney to the bladder. Stents prevent obstruction from the pulverized stone particles, or gravel, following lithotripsy and are generally used only when treating more difficult kidney stone problems, such as large stones, multiple stones, or patients with only one kidney. The stent is temporary and usually remains in place for seven to ten days. A string may be attached to the end of the stent to allow it to be easily removed in the physician's office.
Shock waves appear to be safe and there have been very few side effects directly attributed to them. Rarely (about one in 200 cases), bleeding around the kidney occurs as a result of shock wave lithotripsy therapy. Risk of damage to other internal organs appears to be minimal. Lithotripsy may be associated with slight increases in blood pressure; to date, these changes have not been large enough to cause hypertension.
About one-third of patients will experience some discomfort as they begin to pass the gravel. This pain is usually short lived and easily managed with pain-killing medication. Some blood in the urine will be noted for a day or two following lithotripsy. Most, but not all, patients with kidney stones are candidates for shock wave lithotripsy. The size, location, and number of stones and/or presence of anatomical peculiarities may make other forms of treatment preferable. In some cases, combination treatment, such as ureteroscopic removal of an obstructing stone in the ureter followed by lithotripsy treatment of a kidney stone, may be appropriate.
Extremely large or "staghorn" stones are usually surgically treated first by percutaneous lithotripsy (PERC) because such stones do not respond well to shock wave lithotripsy treatment alone.
Some discomfort can be expected during lithotripsy where the shock wave enters the body. If the stone is small, a "low power" setting can often be utilized, allowing treatment while awake. An anesthesiologist will provide small amounts of a sedative, if necessary, to keep you comfortable during treatment. Larger and more complex stones require a "high power" setting on the lithotriptor and usually need a complete, or general, anesthetic. Your urologist will discuss with you the type of anesthesia best suited to treatment of your kidney stone problem.
The entire lithotripsy treatment procedure will last approximately one hour. The urologist performing the treatment monitors stone fragmentation using the fluoroscopes. The amount of radiation received from the fluoroscopes during lithotripsy is about the same as for routine diagnostic x-rays.
Customary charges include professional services and for radiographic, laboratory, and hospital services. You also will be required to pay a fee for the lithotripsy treatment. This fee is comparable to that charged for standard surgical therapy. Lithotripsy is an approved treatment for kidney stones and is covered by most private and government insurance plans.
Typically, you will not need hospitalization after treatment. Blood-tinged urine is to be expected for a few days. Stone particles usually begin to pass within a day or two following treatment and may continue to pass intermittently for several weeks. The passage of particles causes remarkably little discomfort in the majority of patients. Convalescence following treatment is minimal. Most patients have been able to resume full activities within a few days after treatment.
Follow-up evaluation in the doctor's office is very important to judge the treatment's success. This evaluation includes a plain x-ray to assess stone fragmentation, a renal ultrasound to check the kidney, and a urine specimen to check for any signs of infection.
