Urolithiasis, Endourology and Laparoscopy

Urological Survey UROLITHIASIS, ENDOUROLOGY AND LAPAROSCOPY Retrograde Ureteral Stents for Extrinsic Ureteral Obstruction: Nine Years’ Experience at University of Michigan H. M. Rosevear, S. P. Kim, D. L. Wenzler, G. J. Faerber, W. W. Roberts and J. S. Wolf, Jr., Department of Urology, University of Michigan Medical School, Ann Arbor, Michigan Urology 2007; 70: 846 – 850. Objectives: To review our experience with retrograde ureteral stenting for extrinsic ureteral obstruction because previous reports have suggested only moderate success. Methods: We performed a retrospective review of the course of patients who underwent retrograde ureteral stent placement from March 1996 to April 2005. The gathered clinical parameters included stent failure, which was defined as any ureteral unit (UU) that remained obstructed. Results: A total of 54 patients treated for extrinsic ureteral compression, representing 87 UUs, were followed for an average of 16 months (range 0.7 to 98) in successful cases. Of the stents, 68% were placed for malignancy, 23% for retroperitoneal fibrosis, and 9% for benign masses. The overall success rate was 84%, with malignancy, retroperitoneal fibrosis, and benign masses having an 81%, an 85%, and a 100% success rate, respectively. Fourteen UUs failed, with a mean time to stent failure of 4.8 months (range 0.07 to 27). Multiple stents were placed in 54 UUs, with a mean of 5.5 stent exchanges, at a mean interval of 3.6 months. On univariate analysis, only greater posttreatment creatinine was associated with stent failure (P ⬍0.01), although stents placed for localized disease tended to be more successful than those placed for regional disease (100% versus 81%, P ⫽ 0.07). Conclusions: If initial stent placement was possible, extrinsic ureteral obstruction was managed successfully with retrograde ureteral stent placement in 84% of cases. Because no preoperative characteristics could be identified, except for a trend toward less success in cases of regional disease, retrograde stenting can be considered first-line treatment in patients with extrinsic ureteral obstruction. Editorial Comment: In the late 1980s Docimo and DeWolf reported on a large series of patients with extrinsic ureteral obstruction in whom indwelling stents were placed.1 Their results were not encouraging, in that only 56% of the cases could be managed successfully in this manner, with followup only out to 1 month. Now, nearly 20 years later, Rosevear et al note an 84% success rate (81% if the cause is a periureteral malignancy) in an even larger patient population. Furthermore, their mean time to stent failure was 4 times longer than in the prior study, at 4.8 months. They used only 6Fr or 7Fr solitary flexible radiopaque stents. They hypothesize that their improved success rate may have been secondary to changes in stent design and more biocompatible stent material. The bottom line is that for these unfortunate patients stent technology has now advanced to the point where stent placement is a reasonable and successful means of treating obstruction, thereby avoiding placement of a nephrostomy tube. Even among those patients with a failed single stent one may proceed to placement of a double stent (ie 2, 6Fr stents in 1 ureter) or use of the newer long-term nickel-cobalt-chromium-molybdenum alloy stent before relegating an individual, with all too often precious little time to live, to the social indignities of an external tube and its collection device. Ralph Clayman, M.D. 1. Docimo SG and Dewolf WC: High failure rate of indwelling ureteral stents in patients with extrinsic obstruction: experience at 2 institutions. J Urol 1989; 142: 277.

0022-5347/08/1802-0629/0 THE JOURNAL OF UROLOGY® Copyright © 2008 by AMERICAN UROLOGICAL ASSOCIATION

629

Vol. 180, 629-636, August 2008 Printed in U.S.A. DOI:10.1016/j.juro.2008.04.091