title: Endovenous simulated laser experiments at 940 nm and 1470 nm suggest wavelength-independent temperature profiles.
abstract: BACKGROUND
  EVLA has proven to be very successful, but the optimum methods for energy delivery have still not been clarified. A better understanding of the mechanism of action may contribute to achieving a consensus on the best laser method and the most effective use of laser parameters, resulting in optimal clinical outcomes, maintaining high success rates with minimal adverse events. The aim of this study is to assess the impact of wavelength, pullback speed and power level on the endovenous temperature profile in an experimental setting.
  
  
  METHODS
  In an experimental setting, temperature measurements were performed using thermocouples. The experimental set-up consisted of a transparent box in which a glass tube was fixed. Different laser parameters (wavelength and power) and 2 different pullback speeds (2 and 5 mm/s) were used. Thermocouples were placed at different distances from the fiber tip. Validity of the experimental setting was assessed by performing the same temperature measurements using a stripped varicose vein. The maximal temperature rise and the time span that the temperature was above collagen denaturation temperature were measured.
  
  
  RESULTS
  The experiments showed that decreasing the pullback speed (2 mm/s) and increasing the power (up to 14 W) both cause higher maximal temperature and a longer time above the temperature for collagen denaturation. The use of different laser wavelengths (940 or 1470 nm) did not influence the temperature profile.
  
  
  CONCLUSIONS
  The results of our experiments show that wavelength on its own has not been demonstrated to be an important parameter to influence the temperature profile.
authors.affiliation: Department of Dermatology, Erasmus Medical Center, Rotterdam, The Netherlands. r.vandenbos@erasmusmc.nl
authors.forename: R R
authors.initials: RR
authors.lastname: van den Bos
authors.forename: P W M
authors.initials: PW
authors.lastname: van Ruijven
authors.forename: C W M
authors.initials: CW
authors.lastname: van der Geld
authors.forename: M J C
authors.initials: MJ
authors.lastname: van Gemert
authors.forename: H A M
authors.initials: HA
authors.lastname: Neumann
authors.forename: T
authors.initials: T
authors.lastname: Nijsten
mesh_terms: D001831:Body Temperature / Q000502:physiology*; D057510:Endovascular Procedures / Q000379:methods*; D004867:Equipment Design; D006358:Hot Temperature; D006801:Humans; D053685:Laser Therapy / Q000295:instrumentation*; D008954:Models, Biological; D015203:Reproducibility of Results; D012501:Saphenous Vein / Q000503:physiopathology / Q000601:surgery*; D014648:Varicose Veins / Q000503:physiopathology / Q000601:surgery*