title: In vitro evaluation of ScopeSafe fibers and the scope guardian sheath in prevention of ureteroscope endolumenal working damage.
abstract: OBJECTIVE
  Ureteroscope breakage is commonly related to laser fiber damage. Often, the damage is mechanical and not energy related. As such, we evaluated a novel laser fiber and sheath system in preventing mechanical ureteroscope damage during fiber insertion.
  
  
  METHODS
  We assessed 200-μm/272/3-μm laser fibers with the laser sheath in a flexible ureteroscope. Diminishment of active deflection and irrigation flow rates were compared with a standard laser fiber alone. Eight nonassembled working channel components were tested in a 0-degree/90-degree/210-degree deflection model. After insertion cycles, external and endolumenal damage to the working channel were classified. We also tested the sheath system in a 0-degree/90-degree/210-degree deflection model for fiber failure and laser damage.
  
  
  RESULTS
  In all test trials with the sheath and for standard laser fibers in the 0-degree model, there were no channel perforations or damage. With standard laser fibers, in the 210-degree model, superficial scratches and demarcated abrasions were visible after 10 and 60 to 70 insertions for the 273-μm laser fiber and after 30 insertions (superficial scratches) for the 200-μm laser fiber. In the 90-degree model, superficial scratches occurred after 20 insertions for the 273-μm fibers and after 40 insertions for the 200-μm laser fibers. No demarcated abrasions were seen after 100 insertions. In the 210-degree model, there was one perforation with the 272-μm fiber, but none with 200-μm fiber. There were no fiber failures with sheath use; however, the sheath did not prevent laser energy damage. The laser sheath resulted in a 4.7-degree/3.8-degree (1.2%/1.5%) diminishment in deflection (up/down) for the 200 μm and a 3.5-degree/4.3-degree (1.8%/1.5%) diminishment for 272-μm laser fiber compared with standard 200/272-μm laser fiber. Irrigation flow was diminished with the sheath on both the 200-μm and 272-μm laser fiber by 28.7% and 32.6%, respectively.
  
  
  CONCLUSIONS
  The Scope Guardian Sheath prevented mechanical working channel damage with minimal diminishment of deflection and irrigation flow.
authors.affiliation: Department of Urology, University of California, Irvine, Orange, CA 92868, USA. achimlusch@aol.com
authors.forename: Achim
authors.initials: A
authors.lastname: Lusch
authors.forename: Corollos
authors.initials: C
authors.lastname: Abdelshehid
authors.forename: Michael A
authors.initials: MA
authors.lastname: Liss
authors.forename: Reza
authors.initials: R
authors.lastname: Alipanah
authors.forename: Elspeth M
authors.initials: EM
authors.lastname: McDougall
authors.forename: Jaime
authors.initials: J
authors.lastname: Landman
mesh_terms: D004867:Equipment Design; D004868:Equipment Failure; D020709:Ureteroscopes