title: Impact of surgical experience on stone-free rates of ureteroscopy for single urinary calculi of the upper urinary tract: a matched-paired analysis of 600 patients.
abstract: BACKGROUND
  To evaluate the impact of surgical experience on ureteroscopic stone-free rates (SFR) and complication rates (CR) for the treatment of urinary calculi of the upper urinary tract.
  
  
  METHODS
  We evaluated retrospectively, patients (n=300) having undergone ureteroscopy (URS) for single urinary calculi treated by residents (n=12) at our department over a 6-year period. These patients were matched according to age, gender, body-mass index, and stone side/size/site with patients (n=300) treated by consultants (n=5) of our department during the same period. Patient data, primary SFR, and CR were compared.
  
  
  RESULTS
  The mean±standard deviation (range) stone size was 6.39±3.26 (2-20) mm. The primary SFR after one URS procedure was 95.2% and did not differ between residents and consultants (95% vs 95.3%, p=0.489). The SFR were 95.9% and 98.5% for ureteral stones (p=0.125) and 93.2% and 89.3% for kidney stones (p=0.298) in the resident and consultant group, respectively. The SFR differed significantly between ureteral and kidney stones (97.2% vs 91.3%, p≤0.001). Perioperative complications occurred in a total of 63 patients (10.5%): Clavien 1: 3.8%, Clavien 2: 2%, Clavien 3a: 1.8%, and Clavien 3b: 2.8%, respectively. There were no differences in the total CR between residents (12%) and consultants (9%) (p=0.2116). However, the ureteral perforation rate was significantly higher in residents compared with consultants (4.3% vs 1.3%, p≤0.027).
  
  
  CONCLUSIONS
  URS is a safe and efficacious procedure for the treatment of single urinary calculi. Resident status does not compromise the SFR after ureteroscopic treatment of single urinary calculi. However, the incidence of ureteral perforation was associated with surgeon's experience.
authors.affiliation: Department of Urology, Asklepios Hospital Barmbek , Hamburg, Germany .
authors.forename: Christopher
authors.initials: C
authors.lastname: Netsch
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Knipper
authors.forename: Ann Kathrin
authors.initials: AK
authors.lastname: Orywal
authors.forename: Christian
authors.initials: C
authors.lastname: Tiburtius
authors.forename: Andreas J
authors.initials: AJ
authors.lastname: Gross
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007396:Internship and Residency / Q000706:statistics & numerical data*; D007669:Kidney Calculi / Q000601:surgery*; D008297:Male; D016555:Matched-Pair Analysis; D008875:Middle Aged; D011183:Postoperative Complications; D012189:Retrospective Studies; D016896:Treatment Outcome; D014514:Ureteral Calculi / Q000601:surgery*; D018666:Ureteroscopy / Q000379:methods* / Q000706:statistics & numerical data; D014572:Urology / Q000193:education*; D055815:Young Adult