A four-year experience with Holmium-YAG laser:parameters of use.

In the last years, laser has gained increasingly high popularity in Endourology. The newer generation Ho-YAG lasers represent the most updated laser used in Urology, being able to successfully treat both urinary stones and soft tissue lesions. The aim of this work was to report a multicentre 4-year experience using the Ho-YAG laser in the treatment of stones and soft tissue lesions, in order to offer parameters and modalities of use in several different situations. MATERIALS AND METHODS. Two urological Centers were asked between 2002 and 2005 to use Coherent Versa Pulse 20 Ho-YAG laser source in the treatment of urinary stones in 212 patients, and urinary soft tissue lesions (urethra, ureter or bladder neck strictures or urinary tract tumors) in 56 patients. According to the various situations (either stone fragmentation or treatment of soft tissue lesions), pulse frequency and energy per impulse were differently dosed and set. RESULTS. The following parameters were identified as the starting points for the correct use of the Ho-YAG laser: a) lithotripsy with rigid endoscope: 365 μm fiber, 0.8 - 1.2 Joule (J) energy and 6-8 Hz frequency; 365 μm fiber, 0.8-1.2 J energy and 10-12 Hz frequency; 550 μm fiber, 1.0-1.5 J energy and 10-12 Hz frequency. b) lithotripsy with flexible endoscope: 270 μm fiber, 0.6-1.0 J energy and 6-10 Hz frequency. c) soft tissue resection in case of: c1) ureteral stricture, 365 μm fiber, 0.6 J energy and 14-16 Hz frequency; c2) urethral stricture, 365 μm fiber, 0.7 J energy and 16-18 Hz frequency; c3) upper urinary tract tumors, 365 μm fiber, 0.7 J energy and 16 Hz frequency; c4) bladder tumors 365 μm fiber, 0.8 J energy and 16-20 Hz frequency; c5) bladder neck strictures, 365 μm fiber, 1.0 J energy and 16-18 Hz frequency. CONCLUSIONS. In the light of these parameters, Ho-YAG laser is a very handy instrument for the treatment of both urinary stones and soft tissue lesions, which allows to put aside the current tools used for the same purposes.