title: Thulium Laser in the Upper Urinary Tract: Does the Heat Generation in the Irrigation Fluid Pose a Risk? Evidence from an In Vivo Experimental Study.
abstract: The current experimental study aimed at evaluating the temperature raise of the irrigation fluid caused by the use of the thulium (Tm:YAG) and holmium laser (Ho:YAG) in the upper urinary tract (UT) of pigs.
  
  
  
  An experimental setting was designed for the investigation of differences in the temperature of the irrigation fluid in the renal pelvis of a porcine model under different flow rates and laser power settings. The experimental configuration included a single-use flexible ureteroscope, a Tm:YAG and a Ho:YAG laser system. A thermocouple was inserted through a 6F ureteral catheter that was placed parallel to the FlexVue in the renal pelvis. An additional thermocouple was placed next to the renal pelvis after open preparation of the kidney. Irrigation was achieved with either the irrigation bags placed 1 m above the level of the pig or with the use of an irrigation pump (30 and 60 compressions per minute).
  
  
  
  Tm:YAG (10, 20, 30, 40 W): The higher flow provided by the pump system minimized the increase of temperature within the renal pelvis regardless of the laser power. The external temperature increase was lower in comparison to the increase inside the renal pelvis. The internal temperature could increase up to 10.5°C from a baseline value of 23°C. Ho:YAG (10, 20 W): There was no temperature change or an increase of only 2.1°C under the different power and irrigation flow rate settings. There were no differences in the temperature between the inside and outside of the renal pelvis.
  
  
  
  The use of Tm:YAG in continuous mode with power settings up to 40 W and flow rates similar to those used in the clinical practice seemed to result in temperature increases in the irrigation fluid, which do not represent a risk for the renal tissue during the UT endoscopic surgery.
authors.affiliation: 1 Department of Urology, University of Patras , Patras, Greece .
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Kallidonis
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: Vasileios
authors.initials: V
authors.lastname: Panagopoulos
authors.affiliation: 1 Department of Urology, University of Patras , Patras, Greece .
authors.forename: Marinos
authors.initials: M
authors.lastname: Vasilas
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: 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: Evangelos
authors.initials: E
authors.lastname: Liatsikos
mesh_terms: D000818:Animals; D004724:Endoscopy; D005260:Female; D006358:Hot Temperature; D007668:Kidney / Q000601:surgery*; D007682:Kidney Pelvis; D007834:Lasers; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D008962:Models, Theoretical; D013552:Swine; D013932:Thulium / Q000627:therapeutic use*; D014551:Urinary Tract / Q000528:radiation effects*
chemical_list: D013932:Thulium