AUA WHITE PAPER ON SHOCK WAVE LITHOTRIPSY: BENEFITS OUTWEIGH RISKS FOR MANY PATIENTS
LINTHICUM, MD, November 24, 2009–The potential benefits of shock wave lithotripsy (SWL) outweigh the foreseeable risks of this treatment, according to a newly released white paper from the American Urological Association (AUA). The AUA developed this white paper in order to provide expert opinion on the safety of SWL, the significance of chronic adverse events and whether the benefits of SWL outweigh the risks.
SWL is a common treatment of stone disease. Urologists often consider treating with SWL when other therapies are unavailable. Although some recent research has shown that SWL, like any surgical procedure, carries risks, experts are saying that the benefits of SWL, sometimes the only procedure available for treatment of stones (a very painful condition), outweighs the risks associated with the procedure.
There is some evidence to show that in addition to scar formation and the long-term loss of functional renal tissue there is a potential link between SWL and the development of diabetes mellitus and new-onset hypertension. However, other evidence has also shown that some stone patients are already at an increased risk of developing diabetes mellitus and hypertension prior to undergoing the procedure. Regardless, experts warn that physicians should be extra vigilant in anticipating and managing these conditions in patients who have undergone SWL treatment.
In the white paper, experts also advocate new measures to reduce the risk of renal injury from SWL. The white paper calls for instituting new pretreatment protocols, including providing a brief, three- to four-minute pause in shock wave delivery soon after the initiation of treatment. Research using animal models has shown that instituting such a pause is protective and reduces bleeding within renal tissue. The white paper also calls for practitioners to slow the shock wave (SW) firing rate to reduce renal injuries and improve stone breakage outcomes. While the typical firing rate is 120 SW per minute, new research shows that slowing the SW-rate to 60 SW per minute could reduce the risk of renal injury. Although the slower rate may require a modest increase in overall treatment time, clinical studies show improved success rates at slower SW-rate and experts say a longer treatment time is preferable to risking renal injury.
More research is necessary to improve SWL and reduce adverse results. The authors state that, “Shock wave lithotripsy is often the best treatment option, in some settings may be the only treatment available and, in most cases, presents distinct advantages that outweigh the foreseeable risks.”
“The field of SWL is continually advancing,” said Dean G. Assimos, MD, a member of the panel that developed the paper. “It is important for all practitioners to be aware of these new treatment protocols so that they can reduce the risk of renal injury for patients suffering from stones.”About the American Urological Association: Founded in 1902 and headquartered near Baltimore, Maryland, the American Urological Association is the pre-eminent professional organization for urologists, with more than 16,000 members throughout the world. An educational nonprofit organization, the AUA pursues its mission of fostering the highest standards of urologic care by carrying out a wide variety of programs for members and their patients.