Experimental verification of thulium lithotripsy

Aim. Experimental evaluation of the efficacy and safety of lithotripsy using a new pulsed thulium fiber laser operating at a wavelength of 1.94 microns, peak power of 500 watts (maximum average power of 50 watts) by comparing it with a holmium laser operating at a wavelength of 2.1 microns (average maximum power 100 W and 120 W). Relevance. The proportion of minimally invasive surgery in the management of urolithiasis, including retrograde intrarenal surgery, is steadily growing. The most appropriate tool for stone destruction is a laser. To date, the gold standard of minimally invasive surgical treatment of nephrolithiasis is holmium laser lithotripsy, which uses a laser on yttrium-aluminum-garnet activated by holmium ions (Ho: YAG) operating at a wavelength of 2.1 pm. However, in recent years, lasers on a Tm-activated fiber with a wavelength of 1.94 pm have become increasingly popular since the water absorption coefficient for the Tm radiation of a fiber laser is 5.5 times higher than for a Ho: YAG laser and in 2.2 times higher than for the Tm: YAG laser. This difference may translate into greater effectiveness and speed of stone crushing, which in turn leads to shorter operating time. Materials and methods. This article describes physical foundations of holmium and thulium laser radiation, the mechanisms of stone fragmentation, data from a series of experiments comparing the efficiency and safety of ex-vivo lithotripsy using a holmium solid-state laser with a wavelength of 2.1 pm and a thulium fiber laser with a wavelength of1.94 pm. Results. The study findings suggest that the STA IRE-Polyus thulium fiber laser operating at a wavelength of 1.94 microns and a maximum power of 500 watts has several advantages over the holmium laser in the stone fragmentation in urological practice. Conclusion. The results of the experimental work allow us to conclude that the use of a thulium fiber laser operating at a wavelength of 1.94 μm and a maximum peak power of 500 W enables highly effective and safe lithotripsy.

laser lithotripsy, urolithiasis, thulium lithotripsy, laser radiation