2022 年 36 巻 1 号 p. 107-114
Calculus crushing factor of TUL (or Ureteroscopy:URS) which is one of the treatments for ureteral stone disease is thermal effect of pulsed laser and collapse impact of laser-induced bubbles. These factors play an important role in crushing calculus, but can cause mechanical and thermal damage to surrounding tissues. In order to improve the safety of TUL, we observed the behavior of bubbles under several laser pulse and energy conditions, and measured temperature around bubbles using a thermocouple. As a result, the bubble behavior changes depending on length of pulse duration. Temperature around long pulse bubble is higher than that in short pulse. The measured temperature was close to one calculated by bubble collapse time based on the Rayleigh’s equation. Long pulse conditions can cause thermal damage to surrounding tissue through examination by cumulative equivalent time at 43 ℃ (CEM43℃).
