Semirigid Ureteroscopy for Ureteral Stones: A Multivariate Analysis of Unfavorable Results

Abstract
Purpose: We determined the factors predicting unfavorable results of semirigid ureteroscopy for ureteral calculi. Materials and Methods: We reviewed the computerized files of 841 patients who underwent a total of 908 ureteroscopic procedures for ureteral stones from January 2003 through December 2006. A semirigid 6/7.5Fr ureteroscope was used in pediatric patients and an 8/10Fr or 8.5/11.5Fr ureteroscope was used in adults. Patients with favorable results were those who became stone-free after a single ureteroscopic procedure without any complications. They were compared with patients who had unfavorable results using univariate (chi-square and t tests) and multivariate (logistic regression) statistical tests to identify risk factors for unfavorable results. Results: The study included 567 males and 274 females with a mean age of 48.5 years (range 2 to 81). The complication rate was 6.7% (61 procedures). The stone-free rate after a single ureteroscopic intervention was 87% (791 procedures). Favorable results were documented in 751 procedures (82.7%). Significant factors for unfavorable results were proximal ureteral stones, ureteroscopy done by surgeons other than experienced endourologists, stone impaction and stone width (relative risk 4, 2.5, 1.8 and 1.2, respectively). Conclusions: Semirigid ureteroscopy is a safe and highly effective treatment modality for ureteral stones.