title: Bilateral same-session ureteroscopy for treatment of ureteral calculi: critical analysis of risk factors.
abstract: OBJECTIVE
  To determine factors affecting the success of bilateral same-session ureteroscopy (BSU) in the treatment of ureteral calculi.
  
  
  METHODS
  From January 2003 to December 2008, BSU was carried out in 89 patients (178 renal units). A successful outcome was considered when both ureters were free of stones without intraoperative complications. Stone-free rate was evaluated with a kidney-ureter-bladder plain X-ray or non-contrast computed tomography. Factors interfering with successful completion of BSU were tested using univariate (chi-squared test and t test) and multivariate (logistic regression) analyses. Data on unilateral ureteroscopy for the treatment of multiple ureteral calculi carried out in 105 patients during the same period were compared with BSU.
  
  
  RESULTS
  Intraoperative complications were recorded in 11 procedures (6.2%) in the form of ureteral perforation in three and mucosal injury in eight. After BSU, 153 renal units were stone free (86%) as 17 had residual fragments, stones migrated to the kidney in six and failure was encountered in two. A successful outcome was observed in 62 patients (70%). Stone impaction, stones located in the proximal ureter and stone surface area were the significant risk factors for unsuccessful BSU (relative risks 3.6, 3.3 and 1.47, respectively). Compared with unilateral ureteroscopy, no difference were found with regard to complication rate (6.7%, p = 0.5) or stone-free rate (80%, p = 0.2).
  
  
  CONCLUSIONS
  Bilateral same-session ureteroscopy is a safe and effective procedure in the management of bilateral ureteral stones. Proximal ureteral calculi, large and impacted stones carry the highest risk of unsuccessful results.
authors.affiliation: Urology and Nephrology Center, Mansoura University, Mansoura, Egypt. a_s_elhefnawy@yahoo.com
authors.forename: Ahmed S
authors.initials: AS
authors.lastname: El-Hefnawy
authors.forename: Ahmed R
authors.initials: AR
authors.lastname: El-Nahas
authors.forename: Nasr A
authors.initials: NA
authors.lastname: El-Tabey
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Shoma
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: El-Assmy
authors.forename: Mahmoud R
authors.initials: MR
authors.lastname: El-Kenawy
authors.forename: Hamdy A
authors.initials: HA
authors.lastname: El-Kappany
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Eraky
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D015994:Incidence; D007431:Intraoperative Complications; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D014513:Ureter / Q000293:injuries; D014514:Ureteral Calculi / Q000601:surgery*; D018666:Ureteroscopy / Q000009:adverse effects* / Q000379:methods*; D055815:Young Adult