Presentation Authors: Laurian Dragos*, Ghiroda, Romania, Bhaskar K. Somani, Southampton, United Kingdom, Keller Etienne X., De Coninck Vincent M.J., Doizi Steeve, Paris, France, Cumpanas Alin A., Martis Sandra M., Timisoara, Romania, Wiseman Oliver J., Cambridge, United Kingdom, Traxer Olivier, Paris, France
Introduction: A novel Super-Pulse Thulium Fiber laser has recently been developed and used for urolithiasis. The initial results show a better efficacy than conventional Holmium laser lithotripsy. The goal of our in-vitro study was to compare the temperature changes between activated High Power Holmium and Super-Pulse Thulium Fiber lasers.
Methods: A Super-Pulse Thulium fiber (SPTF) laser prototype with 200Âµm fibre and a High-Power Holmium (HPH) laser (Lumenis Pulse 120H) with 230Âµm fibre were used. An isothermal box was created and filled with saline (Fig. 1). The temperature of the saline was maintained constantly at 36.5ÂºC using an automated pump which was able to control the pressure and temperature. A urinary tract silicone model was placed in the box with two temperature sensors, one placed within the saline inside the box and the other in the silicone model itself. A LithoVue single-use flexible ureteroscope was introduced through the silicone model without an UAS. Laser fibre tip was placed into a mid calix at 5 mm from the sensor. Laser was activated using different settings until the temperature reached 45ÂºC or for maximum 10 minutes. Experiments were performed without irrigation, with saline irrigation at 40 cm H2O pressure at 20ÂºC and 37ÂºC temperature respectively. All tests were repeated five times.
Results: Our results showed the use of SPTF and HPH laser both caused the temperature to reach 45ÂºC with power greater than 16W, especially when used without irrigation. The time taken (in minutes) to reach this temperature was higher for cooler irrigant fluids._x000D_
With similar energy and frequency settings using both SPTF and HPH laser, no significant differences on temperature was noted for dusting, pop-dusting, fragmenting or pop-corning when using irrigation fluid at 20ÂºC and 37ÂºC (Table 1). On comparison to HPH laser, when similar power but a lower energy SPTF laser was used the later took longer time to reach 45ÂºC although this was not statistically significant (Table 2)
Conclusions: Our results show that both SPTF and HPH laser have similar temperature changes for all stone treatment settings.