title: Lithium triborate laser vaporization of the prostate using the 120 W, high performance system laser: high performance all the way?
abstract: OBJECTIVE
  Technical modifications of the 120 W lithium-triborate laser have been implemented to increase power output, and prevent laser fiber degradation and loss of power output during laser vaporization of the prostate. However, visible alterations at the fiber tip and the subjective impression of decreasing ablative effectiveness during lithium-triborate laser vaporization indicate that delivering constantly high laser power remains a relevant problem. Thus, we evaluated the extent of laser fiber degradation and loss of power output during 120 W lithium-triborate laser vaporization of the prostate.
  
  
  METHODS
  We investigated 46 laser fibers during routine 120 W lithium-triborate laser vaporization in 35 patients with prostatic bladder outflow obstruction. Laser beam power was measured at baseline and after the application of each 25 kJ during laser vaporization. Fiber tips were microscopically examined after the procedure.
  
  
  RESULTS
  Mild to moderate degradation at the emission window occurred in all fibers, associated with a loss of power output. A steep decrease to a median power output of 57.3% of baseline was detected after applying the first 25 kJ. Median power output at the end of the defined 275 kJ lifespan of the fibers was 48.8%.
  
  
  CONCLUSIONS
  Despite technical refinements of the 120 W lithium-triborate laser fiber degradation and significantly decreased power output are still detectable during the procedure. Laser fibers are not fully appropriate for the high power delivery of the new system. There is still potential for further improvement in the laser performance.
authors.affiliation: Department of Urology, University Hospital, University of Zürich, Zürich, Switzerland. thomas.hermanns@usz.ch
authors.forename: Thomas
authors.initials: T
authors.lastname: Hermanns
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Strebel
authors.forename: Lukas J
authors.initials: LJ
authors.lastname: Hefermehl
authors.forename: Oliver
authors.initials: O
authors.lastname: Gross
authors.forename: Ashkan
authors.initials: A
authors.lastname: Mortezavi
authors.forename: Alexander
authors.initials: A
authors.lastname: Müller
authors.forename: Daniel
authors.initials: D
authors.lastname: Eberli
authors.forename: Michael
authors.initials: M
authors.lastname: Müntener
authors.forename: Maurice S
authors.initials: MS
authors.lastname: Michel
authors.forename: Alexander H
authors.initials: AH
authors.lastname: Meier
authors.forename: Tullio
authors.initials: T
authors.lastname: Sulser
authors.forename: Hans-Helge
authors.initials: HH
authors.lastname: Seifert
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001881:Borates; D004867:Equipment Design; D006801:Humans; D053685:Laser Therapy / Q000295:instrumentation / Q000379:methods*; D018020:Lithium Compounds; D008297:Male; D008875:Middle Aged; D011468:Prostatectomy / Q000379:methods*
chemical_list: D001881:Borates; D018020:Lithium Compounds; C021051:lithium borate