title: In vitro and in vivo comparison of optics and performance of a distal sensor ureteroscope versus a standard fiberoptic ureteroscope.
abstract: OBJECTIVE
  Recent advances in distal sensor technologies have made distal sensor ureteroscopes both commercially and technically feasible. We evaluated performance characteristics and optics of a new generation distal sensor Flex-X(C) (X(C)) and a standard flexible fiberoptic ureteroscope Flex-X(2) (X(2)), both from Karl Storz, Tuttlingen, Germany.
  
  
  METHODS
  The ureteroscopes were compared for active deflection, irrigation flow, and optical characteristics. Each ureteroscope was evaluated with an empty working channel and with various accessories. Optical characteristics (resolution, grayscale imaging, and color representation) were measured using United States Air Force test targets. We digitally recorded a renal porcine ureteroscopy and laser ablation of a stone with the X(2) and with the X(C). Edited footage of the recorded procedure was shown to different expert surgeons (n=8) on a high-definition monitor for evaluation by questionnaire for image quality and performance.
  
  
  RESULTS
  The X(C) had a higher resolution than the X(2) at 20 and 10 mm 3.17 lines/mm vs 1.41 lines/mm, 10.1 vs 3.56, respectively (P=0.003, P=0.002). Color representation was better in the X(C). There was no difference in contrast quality between the two ureteroscopes. For each individual ureteroscope, the upward deflection was greater than the downward deflection both with and without accessories. When compared with the X(2), the X(C) manifested superior deflection and flow (P<0.0005, P<0.05) with and without accessory present in the working channel. Observers deemed the distal sensor ureteroscope superior in visualization in clear and bloody fields, as well as for illumination (P=0.0005, P=0.002, P=0.0125).
  
  
  CONCLUSIONS
  In this in vitro and porcine evaluation, the distal sensor ureteroscope provided significantly improved resolution, color representation, and visualization in the upper urinary tract compared with a standard fiberoptic ureteroscope. The overall deflection was also better in the X(C), and deflection as well as flow rate was less impaired by the various accessories.
authors: Department of Urology, University of California, Irvine, Orange, California 92868, USA. achimlusch@aol.com
authors: Achim
authors: A
authors: Lusch
authors: Corollos
authors: C
authors: Abdelshehid
authors: Guy
authors: G
authors: Hidas
authors: Kathryn E
authors: KE
authors: Osann
authors: Zhamshid
authors: Z
authors: Okhunov
authors: Elspeth
authors: E
authors: McDougall
authors: Jaime
authors: J
authors: Landman
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004867:Equipment Design; D055100:Optical Fibers; D015203:Reproducibility of Results; D013552:Swine; D014515:Ureteral Diseases / Q000175:diagnosis*; D020709:Ureteroscopes; D018666:Ureteroscopy / Q000379:methods*
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