Prospective Study of the Long-Term Effects of Shock Wave Lithotripsy on Renal Function and Blood Pressure Waleed A. Eassa, Khaled Z. Sheir,* Hossam M. Gad, Mohamed E. Dawaba, Mahmoud R. El-Kenawy and Hamdy A. Elkappany From the Departments of Urology (WAE, KZS, MED, MRE, HAE) and Radiology (HMG), Urology and Nephrology Center, Mansoura University, Mansoura, Egypt Purpose: We clarified the long-term effects of extracorporeal shock wave lithotripsy on renal function and blood pressure, and its relation to body mass index and type of lithotriptor. Materials and Methods: A total of 100 patients with a single radiopaque renal stone 2 cm or less in length were followed for 18 to 57 months (mean 43.6  13.8) after being stone-free by extracorporeal shock wave lithotripsy monotherapy using 2 lithotriptors. Mean patient age was 47.9  9.1 years (range 23 to 66). Nuclear scintigraphy using 99m technetium- mercaptoacetyltriglycine was done for all patients before extracorporeal shock wave lithotripsy, as well as at the last followup visit to estimate glomerular filtration rate, clearance and split renal function. Blood pressure measurements were recorded at admission and at each followup visit. Results: Before extracorporeal shock wave lithotripsy treated side mean 99m technetium-mercaptoacetyltriglycine clearance, glomerular filtration rate and split function were 146.22  59.48, 52.66  13.69 and 49.7  7.31, respectively. At the last followup visit they were 145.1  58.82 (p = 0.842), 54.85  15.75 (p = 0.114) and 49.96  8.68 (p = 0.577), respectively. Of 100 patients 18 were hypertensive before extracorporeal shock wave lithotripsy and 21 were hypertensive at the last followup visit. Mean diastolic blood pressure before extracorporeal shock wave lithotripsy was 80.2  6.2 vs 80.6  7.8 mm Hg (p = 0.674) at the end of followup. Mean systolic blood pressure before extracorporeal shock wave lithotripsy was 121.2  9 vs 121.55  10.2 mm Hg by the end of the study (p = 0.748). There were no statistically significant differences among body mass index groups or lithotriptor groups. Conclusions: Extracorporeal shock wave lithotripsy is a safe procedure and has no significant long-term effects on renal function or blood pressure regardless of the type of machine used or body mass index. Key Words: lithotripsy, urinary calculi, radionuclide imaging, blood pressure, clinical trials C urrently extracorporeal shock wave lithotripsy is an effective first line treatment for renal stones. Al- though it is noninvasive, SWL studies in animals and humans showed dose dependent, short-term and long-term adverse effects. These changes are secondary to the cellular and microvascular effects of trauma, hemorrhage, ischemia and free radical formation. 1,2 SWL causes vascular insult in which capillaries and small vessels are torn with resulting sites of parenchymal and subcapsular hemorrhage. These factors lead to tubular and interstitial cell injury with sub- sequent infiltration of inflammatory cells, fibrosis and scar- ring. The effects of these changes ultimately manifest clini- cally as loss of renal function, hypertension and an accelerated rate of stone recurrence. 2 Some investigators view SWL induced changes in renal function as transient 3 whereas others view them as longer lasting. 4 However, long-term study of the effects of SWL on adult human renal paren- chyma with subsequent functional changes and possible risk factors is still needed. In this study we evaluated the long-term effects of SWL on renal function using radionu- clide scan and investigated possible post-SWL changes in blood pressure. PATIENTS AND METHODS A prospective study included 120 consecutive patients with a single radiopaque renal stone 2 cm or less in length and with normal contralateral kidney who were admitted to our center for SWL monotherapy starting in March 1999. All patients were followed until December 2004. Other eligibil- ity criteria included absence of any history of urolithiasis or previous urological intervention, absence of ureteral stent or nephrostomy tube that could interfere with radionuclide test results, and absence of obstruction on pretreatment renal US and renal scans. Patients were excluded from the study if they needed any other urological intervention for the kid- neys during followup or if they had residual fragments at Submitted for publication May 13, 2007. Nothing to disclose. Study received local ethics committee approval. * Correspondence: Department of Urology, Urology and Ne- phrology Center, Mansoura University, 72 Elgomhoria St., 35516 Mansoura, Egypt (telephone: +2050-2262222; FAX: +2050-2263717; e-mail: kzsheir@hotmail.com). Editor’s Note: This article is the fourth of 5 published in this issue for which category 1 CME credits can be earned. Instructions for obtaining credits are given with the questions on pages 1208 and 1209. Urolithiasis/Endourology 0022-5347/08/1793-0964/0 Vol. 179, 964-969, March 2008 THE JOURNAL OF UROLOGY ® Printed in U.S.A. Copyright © 2008 by AMERICAN UROLOGICAL ASSOCIATION DOI:10.1016/j.juro.2007.10.055 964