title: Retrograde intrarenal surgery as second-line therapy yields a lower success rate.
abstract: OBJECTIVE
  Retrograde intrarenal surgery (RIRS) is a recent addition to the treatment options for renal calculi. Therefore, the indications, as well as the predictors of success, are still being studied. Herein, we report a retrospective comparison of RIRS performed as the primary treatment and as second-line therapy, mostly after shockwave lithotripsy (SWL) failure.
  
  
  METHODS
  Between October 2001 and August 2004, 93 patients underwent RIRS (11% of all ureteroscopies), all by the same surgeon. Patients were divided into two groups: group 1 (n = 42) consisted of patients undergoing RIRS as a first-line modality and group 2 (n = 51) of those having RIRS as secondline therapy. The indications for RIRS in group 1 were renal calculi with prior placement of a double-J stent (30%), renal + ureteral stone (25%), pushback of ureteral stone during ureteroscopy (22%), a radiolucent stone (8%), coagulopathy, and abnormal renal anatomy. In group 2, the patients were initially treated by SWL (92%) or percutaneous nephrolithotomy. The groups did not differ significantly in demographic characteristics, mean stone size (9.5 and 8.7 mm, respectively), or stone location (in both 60% in the lower pole). The variables analyzed were operating time, complications, length of hospitalization, and stone-free rate.
  
  
  RESULTS
  The overall stone-free rate was 73%. However, the stone-free rate was significantly higher in group 1 than in group 2: 80% v 67%, respectively. A higher complication rate and longer hospitalization were noted in group 2, although the difference was not statistically significant.
  
  
  CONCLUSIONS
  When RIRS is performed after failed SWL, it has a lower success rate and may be associated with a higher morbidity rate than if it is performed as first-line therapy. These results suggest that the success rate of RIRS may be influenced by the same negative factors that reduce SWL success. Therefore, if a patient fails SWL, careful consideration should be given to the best second-line therapy comparing RIRS with percutaneous stone removal.
authors.affiliation: Minimally Invasive Urology, Rabin Medical Center, Petach Tikva, Israel.
authors.forename: R
authors.initials: R
authors.lastname: Holland
authors.forename: D
authors.initials: D
authors.lastname: Margel
authors.forename: P M
authors.initials: PM
authors.lastname: Livne
authors.forename: D M
authors.initials: DM
authors.lastname: Lask
authors.forename: David A
authors.initials: DA
authors.lastname: Lifshitz
mesh_terms: D005260:Female; D006801:Humans; D007668:Kidney / Q000601:surgery*; D007669:Kidney Calculi / Q000601:surgery*; D008096:Lithotripsy; D008297:Male; D016879:Salvage Therapy / Q000379:methods; D016896:Treatment Outcome; D018666:Ureteroscopy / Q000379:methods*