title: Does the Heat Generation by the Thulium:Yttrium Aluminum Garnet Laser in the Irrigation Fluid Allow Its Use on the Upper Urinary Tract? An Experimental Study.
abstract: BACKGROUND
  The current experimental study aimed into evaluating the temperature raise of the irrigation fluid caused by the use of the Thulium:Yttrium aluminum garnet (Tm:YAG) laser. The study setting was designed to replicate conditions of upper urinary tract (UT) surgery.
  
  
  METHODS
  An experimental setting was designed for the investigation of differences in the temperature of the irrigation fluid in different flow rates, laser power settings, and laser activation times and modes. The experimental configuration included a burette equipped with a micrometric stopcock, a thermocouple, and a modified 40-mL vessel. A Tm:YAG and Holmium:Yttrium aluminum garnet (Ho:YAG) laser devices were used.
  
  
  RESULTS
  The Tm:YAG in the continuous mode and in power settings of 5, 10, and 20 W showed similar temperature changes during the 10-minute observation period. The temperatures of the Tm:YAG in the pulsed mode tended to range within similar levels (46.8°C-61°C) with the continuous mode (47.8°C-68°C) when power settings up to 20 W were considered. When the higher power settings (50 and 100 W) were investigated, the temperatures reached were significantly higher in both pulsed and continuous modes. The Ho:YAG showed similar temperatures in comparison to the Tm:YAG in all the flow rates and power settings. The temperatures ranged between 45.6°C and 68.7°C.
  
  
  CONCLUSIONS
  The Tm:YAG in the pulsed and continuous mode with power settings up to 20 W seemed to have potential for UT use. By combining a power setting at the above limit and a low flow rate (as low as 2 mL/minute), it is possible to use the Tm:YAG with safety in terms of temperature.
authors.affiliation: 1 Department of Urology, University of Patras , Patras, Greece .
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Kallidonis
authors.affiliation: 2 Department of Chemical Engineering, University of Patras , Patras, Greece .
authors.forename: Lefteris
authors.initials: L
authors.lastname: Amanatides
authors.affiliation: 1 Department of Urology, University of Patras , Patras, Greece .
authors.forename: Vasileios
authors.initials: V
authors.lastname: Panagopoulos
authors.affiliation: 1 Department of Urology, University of Patras , Patras, Greece .
authors.forename: Iason
authors.initials: I
authors.lastname: Kyriazis
authors.affiliation: 3 Department of Anesthesiology and ICU, University of Patras , Patras, Greece .
authors.forename: Theofanis
authors.initials: T
authors.lastname: Vrettos
authors.affiliation: 3 Department of Anesthesiology and ICU, University of Patras , Patras, Greece .
authors.forename: Fotini
authors.initials: F
authors.lastname: Fligou
authors.affiliation: 1 Department of Urology, University of Patras , Patras, Greece .
authors.forename: Wissam
authors.initials: W
authors.lastname: Kamal
authors.affiliation: 1 Department of Urology, University of Patras , Patras, Greece .
authors.forename: Evangelos N
authors.initials: EN
authors.lastname: Liatsikos
mesh_terms: D000535:Aluminum; D006695:Holmium / Q000627:therapeutic use; D006358:Hot Temperature; D006801:Humans; D053685:Laser Therapy / Q000295:instrumentation*; D053844:Lasers, Solid-State; D008297:Male; D011470:Prostatic Hyperplasia / Q000601:surgery*; D013696:Temperature; D007507:Therapeutic Irrigation; D013932:Thulium / Q000627:therapeutic use; D014551:Urinary Tract / Q000528:radiation effects*; D015019:Yttrium
chemical_list: C503779:yttrium-aluminum-garnet; D015019:Yttrium; D013932:Thulium; D000535:Aluminum; D006695:Holmium