[Lasers in urology : Relevant principles].

A fundamental understanding of the physical properties is necessary for the application of lasers in medicine in order to be able to understand and appreciate the biological effect. The most important parameters are emission mode, wavelength of the laser and power output measured in watts. Pulsed lasers can be used for the treatment of stones and soft tissues, whereby in urology this essentially applies to the prostate gland and to a lesser extent also for the ureter, urethra, bladder and kidneys.