title: Effectiveness of flexible ureteroscopic stone removal for treating ureteral and ipsilateral renal stones: a single-center experience.
abstract: OBJECTIVE
  The aim of this study was to evaluate the effectiveness of simultaneous flexible ureteroscopic removal of stones (URS) for ureteral and ipsilateral renal stones and to analyze the predictive factors for renal stone-free status.
  
  
  METHODS
  We retrospectively reviewed the records of patients who underwent simultaneous flexible URS of ureteral and ipsilateral renal stones from January 2010 to May 2012. All operations used a flexible ureteroscope. We identified 74 cases of retrograde intrarenal surgery and 74 ureteral stones (74 patients). Stone-free status was respectively defined as no visible stones and clinically insignificant residual stones <3 mm on a postoperative image study. Predictive factors for stone-free status were evaluated.
  
  
  RESULTS
  The immediate postoperative renal stone-free rate was 70%, which increased to 83% at 1 month after surgery. The immediate postoperative ureteral stone-free rate was 100%. Among all renal stones, 15 (20.3%) were separately located in the renal pelvis, 11 (14.8%) in the upper calyx, 15 (20.3%) in the mid calyx, and 33 (44.6%) in the lower calyx. The mean cumulative stone burden was 92.22±105.75 mm(2). In a multivariate analysis, cumulative stone burden <100 mm(2) was a significant predictive factor for postoperative renal stone-free status after 1 month (p<0.01).
  
  
  CONCLUSIONS
  Flexible URS can be considered simultaneously for both ureteral and renal stones in selected patients. Flexible URS is a favorable option that promises high stone-free status without significant complications for patients with a stone burden <100 mm(2).
authors.affiliation: Department of Urology, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Sang Hyup
authors.initials: SH
authors.lastname: Lee
authors.forename: Tae-Hyoung
authors.initials: TH
authors.lastname: Kim
authors.forename: Soon Chul
authors.initials: SC
authors.lastname: Myung
authors.forename: Young Tae
authors.initials: YT
authors.lastname: Moon
authors.forename: Kyung Do
authors.initials: KD
authors.lastname: Kim
authors.forename: Jung Hoon
authors.initials: JH
authors.lastname: Kim
authors.forename: Jong Kyou
authors.initials: JK
authors.lastname: Kwon
authors.forename: In Ho
authors.initials: IH
authors.lastname: Chang
keywords: Kidney calculi; Lithotripsy; Treatment outcome