Fragmentation targeted at preferred discontinuities: A new concept in endolithotripsy with Holmium laser:YAG. / Fragmentación dirigida a discontinuidades preferentes: un nuevo concepto en endolitotricia con láser Holmium:YAG.

INTRODUCTION: There are currently 3holmium laser, YAG (Ho:YAG) endolithotripsy procedures that are considered basic (fragmentation, pulverisation, "pop-corn" technique). We present the technique of fragmentation targeted at preferred discontinuities (FTPD), a new concept of endolithotripsy by Ho:YAG laser. MATERIAL AND METHODS: The FTPD technique is based on the selective application of energy (targeting a specific preselected point) to an area that is visually prone to the formation of a fracture line or preferred discontinuity (conditioned by the anisotropy of the urolithiasis). The ideal energy regimen (setting) is a high range of working energy (2-3J) with a very low frequency range (5-8Hz) and short pulse width. Between January 2015 to February 2017, the FTPD technique was used in 37 procedures (7 NLP, 16 RIRS, 12 URS, 2 cystolithotomies), with a Ho:YAG laser (Lumenis Pulse 120H®, Tel-Aviv, Israel). Maximum power used: 24W (3J/8Hz) with fibres of 365µ and 273µ (URS, RIRS), and 32W (4J/8Hz) with fibres of 550µ (NLP, cystolithotomy). RESULTS: Strategic improvement was achieved in all cases using the TFPD technique to continue the endolithotripsy or remove fragments. No complications were recorded after the use of this method. CONCLUSIONS: FTPD can be considered a complementary option in combination with the basic methods of fragmentation and pulverisation. In our experience, it constitutes significant progress in optimising the performance of Ho:YAG laser endolithotripsy.