Prospects for Using a Pulsed Tm-Doped Fiber Laser for Lithotripsy of Salivary Stones

Laser lithotripsy using optical fiber to fragment salivary gland stones (sialoliths) is currently one of the most successful methods for treating salivary stone disease. It is important to reduce the fragmentation time of extremely hard salivary stones, which in practice is more than three hours in the case of large stones. We present new approaches to lithotripsy related to the use of radiation from a nanosecond thulium-doped fiber laser at a wavelength of 1.94 mu m. The study is performed using gypsum phantoms and sialoliths. Parameters of laser exposure are determined that provide a high rate of lithotripsy without significant heating of surrounding tissues. It is shown that the mechanism of action of nanosecond laser radiation, which is well absorbed in water upon fragmentation of stones, is associated with the burnout of the binding organic material of sialolite and the explosive boiling of water. The results obtained can serve as the basis for the development of new promising medical technology.