Laser safety, warnings, and limits in retrograde intrarenal surgery.

ABSTRACT

OBJECTIVE: To analyze the current information about laser safety in retrograde intrarenal surgery (RIRS), focusing on the two main laser technologies that we use in urology, the holmiumyttrium-aluminum-garnet (HoYAG) laser, and the thulium fiber laser (TFL). METHODS: Narrative overview of the most relevant articles published in MEDLINE and Scopus databases about this subject. RESULTS: TFL and HoYAG laser at similar settings (0.2 J/40 Hz) have similar volume-averaged temperature increase and the average heating rate increase proportionally to laser power, especially when high frequencies are used. Recent preclinical data, comparing both laser technologies at different laser settings, agreed that when the delivered energy increases in expenses of higher frequencies, the thermal damage increases too. Higher frequencies, despite of the rise of temperature in the irrigation medium, can cause accidental thermal lasering lesions. CONCLUSION: The use of low frequency settings and a proper irrigation is critical to avoid thermal injury in endoscopic laser lithotripsy. In addition, the use of laser safety eyeglasses is recommended in HoYAG and TFL ELL.