0022-5347/97/1582-0356$03.00/0 THE JOURNAL OF UROLOGY Copyright 0 1997 by AMERICAN UROLOCICAL ASSOCIATION, INC.

Vol. 158, 356. August 1997 Printed in U.S.A.

EDITORIAL: LEAVE NO STONE UNTURNED? It has been 17 years since the first patient was treated with

extracorporeal shock wave lithotripsy. A wave of enthusiasm propelled this new technology, which had promised to be highly effective and complication-free. While shock wave lith- otripsy has revolutionized our management of urinary tract stones, it has not been the Ymagic bullet" for which we had hoped. The American Urological Association guidelines on staghorn calculi and results from the lower pole study group have helped to define appropriate indications as well as lim- itations of shock wave lithotripsy. However, important ques- tions remain unanswered. How aggressive should one be to render a patient stone-free? What is the fate of residual fragments after shock wave lithotripsy? Are residual frag- ments significant or insignificant? What is the risk of devel- oping hypertension after lithotripsy? Insights into these questions are found in 3 articles in this issue of the Journal.

Streem et a1 (page 342) report on their experience with 100 consecutive patients with extensively branched renal calculi managed with combination "sandwich" therapy. Their proto- col consists of percutaneous debulking followed by shock wave lithotripsy and secondary nephroscopy. This aggressive approach rendered approximately 70% of these challenging patients stone-free. Ipsilateral stones recurred in 22.8% of these patients. A multimodal approach is recommended to achieve the highest stone-free rate possible in these patients with a large stone burden.

In 1986 Lingeman et a1 defined the term clinically insig- nificant residual fragments as those that are asymptomatic, smaller than 5 mm. in diameter, not composed of struvite and associated with sterile urine.' Long-term results of the fate of these fragments were not available at that time. In 1996 Streem et al found that 43% of patients with residual frag- ments after shock wave lithotripsy had symptoms or required intervention.* They believed that the term clinically insignif- icant fragments was a misnomer. Zanetti et a1 (page 352) report on 129 patients followed aRer shock wave lithotripsy, of whom 22% required intervention during a 2-year period. They conclude that residual fragments after lithotripsy do not require systematic treatment in the short term.

Based on this study and those in the literature, how should residual fragments after shock wave lithotripsy be best man- aged? Residual fragments do appear to be significant with a natural history of growth and symptoms. True success should not be declared until a stone-free state has been achieved. Many patients will pass these fragments spontaneously, and

should be given the opportunity to do so. The age and medical condition of the patient as well as the location of the frag- ments and the anatomy of the collecting system are factors that should be considered in deciding whom to re-treat.

One must continually balance the expected benefits from shock wave lithotripsy with potential adverse effects and long-term sequelae. The subject of lithotripsy and hyperten- sion has been controversial. While lithotripsy has been ex- tremely well tolerated by most patients, a relationship be- tween it and hypertension has been demonstrated.3 Janetschek et al (page 346) report on a correlation between elevated resistive index values and hypertension in patients older than 60 years. The resistive index continued to increase in 9 patients older than 60 years who had hypertension (45%). This finding seems to identify a subgroup of patients who are more susceptible to hypertension after shock wave lithotripsy. The authors suggest that lithotripsy may lead to a decrease in renal plasma flow, which is consistent with the increase in the resistive index identified.

Extracorporeal shock wave lithotripsy has truly revolu- tionized the way we manage urinary tract stones. I t should not necessarily be applied to every stone and it is not complication-free. Studies such as these 3 articles help to define appropriate indications and optimal patient selection. Residual fragments after shock wave lithotripsy are, in fact, significant. In general terms we should "leave no stone un- turned."

Gary C. Bellman Department of Urology Kaiser Permanente Los Angeles, California

REFERENCES

1. Lingeman, J. E., Newman, D., Mertz, J. H. O., Mosbaugh, P. G., Steele, R. E., Kahnoski, R. J., Coury, T. A. and Woods, J. R.: Extracorporeal shock wave lithotripsy: Methodist Hospital of Indiana experience. J. Urol., 135 1134, 1986.

2. Streem, S. B., Yost, A. and Mascha, E.: Clinical implications of clinically insignificant stone fragments aRer extracorporeal shock wave lithotripsy. J. Urol., 155: 1186, 1996.

3. Lingeman, J. E., Woods, J. R. and Toth, P. D.: Blood pressure changes following extracorporeal shock wave lithotripsy and other forms of treatment for nephrolithiasis. J.A.M.A., 283: 1789, 1990.

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