title: Complications of Flexible Ureteroscopic Treatment for Renal and Ureteral Calculi during the Learning Curve.
abstract: BACKGROUND
  The flexible ureterorenoscope (URS) and associated devices have developed rapidly. However, despite its therapeutic benefits, URS may be associated with some complications. To the best of our knowledge, there are no studies discussing the complications of flexURS during the learning curve.
  
  
  METHODS
  A retrospective review of the records of patients who underwent flexURS from January 2005 to June 2013 was performed. To compare the complications after the introduction of flexURS, patients were divided into four groups based on the surgeon's training experience, that is, based on the number of cases performed by the surgeon. A total of 219 cases underwent flexURS. Groups 1, 2, 3, and 4 included 35, 50, 50, and 84 cases, respectively. The complications were classified using the Clavien system (I-IV).
  
  
  RESULTS
  The mean operation time and stone-free rate were significantly different (p < 0.001, p = 0.013, respectively). The total complication rates were 13.6, 10, 8.3, and 3.2%, respectively (p = 0.068). The more the surgeon's experience, the less was the complication rate. Despite our best efforts, the incidence of urosepsis was not reduced (p = 0.902).
  
  
  CONCLUSIONS
  To reduce severe complications, it is necessary to have performed about 100 cases. Increased surgeon experience tended to decrease the risk of severe complications, but the incidence of urosepsis was not reduced.
authors.affiliation: Department of Urology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan.
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Komori
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Izaki
authors.forename: Kei
authors.initials: K
authors.lastname: Daizumoto
authors.forename: Megumi
authors.initials: M
authors.lastname: Tsuda
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Kusuhara
authors.forename: Hidehisa
authors.initials: H
authors.lastname: Mori
authors.forename: Junichiro
authors.initials: J
authors.lastname: Kagawa
authors.forename: Kunihisa
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: Yasuyo
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Tomoharu
authors.initials: T
authors.lastname: Fukumori
authors.forename: Masayuki
authors.initials: M
authors.lastname: Takahashi
authors.forename: Hiro-Omi
authors.initials: HO
authors.lastname: Kanayama
authors.forename: Manabu
authors.initials: M
authors.lastname: Sakaki
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Nakatsuji
authors.forename: Takumi
authors.initials: T
authors.lastname: Hamao
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Miura
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000601:surgery*; D059032:Learning Curve; D008297:Male; D008875:Middle Aged; D061646:Operative Time; D012189:Retrospective Studies; D012306:Risk; D018805:Sepsis / Q000517:prevention & control; D014513:Ureter / Q000601:surgery; D014514:Ureteral Calculi / Q000601:surgery*; D020709:Ureteroscopes; D018666:Ureteroscopy / Q000009:adverse effects*; D014572:Urology / Q000193:education*; D055815:Young Adult