Calculi

Most calculi that are lodged in the ureter but are not causing excruciating pain for the patient can best be managed initially by observation without resorting to surgery, according to new treatment guidelines issued by the American Urological Association (AUA). Because urologic technology and intervention techniques have increased the choices for the management of ureteral calculi, the AUA convened the Ureteral Stones Clinical Guidelines Panel and charged it with the task of developing practice recommendations based primarily on outcomes evidence from the literature. Joseph Segura, M.D., of the Mayo Clinic, was chair of the AUA panel.

The panel reviewed and analyzed articles related to ureteral calculi that were published from 1966 through January 1996. The guidelines, "Report on the Management of Ureteral Calculi," are the result of the panel's efforts. A summary of the report was published in the November 1997 issue of the Journal of Urology. A "Doctor's Guide for Patients" and "Evidence Working Papers" can be purchased from the AUA Health Policy Department by calling 410-223-4367.

The report contains discussions on the methodology used for developing evidence-based recommendations, characteristics of ureteral calculi and their management, outcomes analysis for ureteral calculi treatment alternatives and ureteral calculi treatment recommendations. Techniques for managing ureteral calculi are explained. A list of all of the articles that were analyzed by the panel is also included. The following is information excerpted from the report:

There are five accepted choices for treating patients with ureteral calculi. These are observation, extracorporeal shock wave lithotripsy, ureteroscopy, percutaneous nephrolithotomy and open surgery (referring to any method of open surgical exposure of the ureter and removal of stones). Also, in special circumstances, laparoscopy is used as a salvage procedure. A traditional treatment alternative is blind basket extraction. According to the panel, blind basketing, even when augmented with use of fluoroscopy and guide wires, is no longer the most efficacious therapeutic choice.

The panel defines the standard patient as a nonpregnant adult who has a solitary ureteral stone composed of material other than cystine or uric acid, who has not been previously treated for this stone, whose medical condition permits performance of any of the accepted active treatment modalities including use of anesthesia, and whose situation is such that all accepted modalities are available and whose condition permits use of any of these modalities.

The panel emphasizes that most (up to 98 percent) of ureteral calculi are small enough to pass spontaneously with a controllable degree of patient discomfort. Smaller stones were defined in the report as those less than 0.5 cm in diameter. Observation with periodic evaluation is recommended for initial treatment of stones with a high probability of spontaneous passage (see table). The panel recommends use of narcotic analgesics and nonsteroidal anti-inflammatory drugs to control pain in the interim before passage of the stone.

The panel does not believe that any method of open surgical exposure of the ureter and removal of calculi should be considered as a first-line treatment option because of the increased risk of morbidity and longer periods of hospitalization. The more aggressive treatment approaches, such as shock wave lithotripsy, ureteroscopy and percutaneous nephrolithotomy, are recommended for patients with larger stones or more severe symptoms. For example, the presence of excruciating pain or kidney infection warrants urgent intervention regardless of the size of the stone.

Of the more aggressive treatment approaches, the panel recommends the following:

* Shock wave lithotripsy is the first-line treatment option for patients with calculi that are I cm or smaller in diameter and are lodged in the upper ureter. Routine stenting to increase the efficiency of fragmentation is not recommended as part of shock wave lithotripsy.

* Shock wave lithotripsy, percutaneous nephrolithotomy and ureteroscopy are all acceptable treatment choices for calculi that are greater than 1 cm in diameter and are lodged in the proximal ureter.

* Both shock wave lithotripsy and ureteroscopy are acceptable treatment choices for all stones lodged in the distal ureter.

The panel emphasizes that shock wave lithotripsy and ureteroscopy each have advantages and disadvantages to be considered. Shock wave lithotripsy is minimally invasive but may require multiple primary treatments for adequate fragmentation and is more likely to require ancillary treatment. Ureteroscopy has a higher success rate, with the least risk of requiring multiple treatments and the least risk of an ancillary procedure, but it is more invasive.

Shock wave lithotripsy and ureteroscopy are now used in the majority of situations in which percutaneous nephrolithotomy was once used, according to the panel. However, the panel states that large stones or complex, impacted stones in the proximal ureter are often best managed by percutaneous nephrolithotomy. One of the advantages of this procedure is that if the stone can be visualized, it can almost always be destroyed. The procedure is also quick, and the results are immediately known. One disadvantage is that not as many physicians are trained to do this procedure as they once were.

The AUA strongly recommends that any patient who has a ureteral stone with a low probability of spontaneous passage be informed about the existing active treatment choices, including the relative benefits and risks associated with each one. The report states that "although, as a practical matter, it is evident that the availability of equipment and the expertise of an individual practitioner may affect the choice of a treatment intervention, it is unacceptable to withhold certain treatments from the patient and not offer them as alternatives because of personal inexperience or unfamiliarity with one of the accepted treatment modalities or because of the local unavailability of equipment or expertise."

According to the panel, the three major challenges for further research are the prevention of calculi, the development of a uniform system of calculi reporting, and the ability to predict the response of calculi to shock wave lithotripsy. Recent developments include use of small flexible ureteroscopes and intracorporeal. lithotripsy devices (laser). The evidence regarding the effectiveness of these new devices is limited.

Patients and the general public can receive information and advice regarding calculi by contacting the Kidney Health Council of the American Foundation for Urologic Disease, 7128 N. Charles St, Baltimore, MD 21201 (telephone: 410-468-1800); the National Kidney Foundation, 30 E. 33rd St, New York, NY 21201 (800-622-9010), or the National Kidney and Urologic Diseases Information Clearinghouse, 3 Information Way, Bethesda, MD 20892-3580 (telephone: 301-654-4415).

COPYRIGHT 1998 American Academy of Family Physicians
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