title: Improving flexible ureterorenoscope durability up to 100 procedures.
abstract: OBJECTIVE
  Controversy exists in the literature regarding flexible ureterorenoscopy (F-URS) durability, with a variable expected number of uses from a new F-URS. In this study, a tertiary center experience with the use of two consecutive F-URS is reported and suggestions as to how to improve durability further are made.
  
  
  METHODS
  All F-URS performed in the same tertiary care center between July 2009 and February 2011, with two new instruments Flex-X, were reviewed retrospectively. All renal pathology were included. Ureteral cases were excluded. A 9.5F semirigid ureteroscope was always used at the start for a ureteral optical predilation and to explore the upper urinary tract for possible lithotripsy/laser ablation/biopsy. The F-URS was introduced sequentially to explore the remaining calices. Data pertaining to the procedure were collected. The method of sterilization was complete immersion with Cidex®.
  
  
  RESULTS
  The instruments were substituted after 113 and 102 procedures, respectively. The first F-URS was used for a total operative time of 79 hours and 10 minutes while the second one was used for 71 hours and 25 minutes (mean 75 hours and 15 min). Procedure duration was 15 to 175 minutes (mean 58 min). The flexible instruments were used for a mean of 42 minutes per procedure (range 13-153 min). The indications for F-URS were therapeutic in 75.4% and diagnostic in 22.8% of the cases. For lower pole calculi, the stone was relocated in 65.2% and managed with the nonflexed flexible instrument 90% of the time. The most common causes of damage of F-URS were: Deflection mechanism impairment, inner sheath damage, and fiberoptic bundle breaks.
  
  
  CONCLUSIONS
  Increased durability of F-URS was from a variety of factors, a key element of which was the method of sterilization, while routine use of the semirigid instrument initially further contributed significantly to increase the number of F-URS procedures, saving overall costs.
authors.affiliation: Department of Urology, Cristo Re Hospital, Via delle calasanziane 25, Rome, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Defidio
authors.forename: Mauro
authors.initials: M
authors.lastname: De Dominicis
authors.forename: Luca
authors.initials: L
authors.lastname: Di Gianfrancesco
authors.forename: Gerhard
authors.initials: G
authors.lastname: Fuchs
authors.forename: Anup
authors.initials: A
authors.lastname: Patel
mesh_terms: D004867:Equipment Design / Q000639:trends; D005336:Fiber Optic Technology / Q000639:trends*; D006801:Humans; D008096:Lithotripsy / Q000379:methods* / Q000592:standards; D012189:Retrospective Studies; D020709:Ureteroscopes / Q000592:standards*; D018666:Ureteroscopy / Q000379:methods / Q000592:standards*; D014545:Urinary Calculi / Q000175:diagnosis / Q000628:therapy*