Flexible ureteroscopy using a 120-w holmium laser: The low-energy/high-frequency approach

With the spread of more powerful lasers and the advent of new technologies, endoscopic interventions for urolithiasis are continuously evolving. The aim of this study is to present our experience and technique regarding Low Energy (LE)/High Frequency (HF) lithotripsy by using a 120-W Holmium laser (Lumenis®). METHODS: We retrospectively analysed our prospectively maintained Retrograde Intra Renal Surgery (RIRS) database. Lithotripsy was performed using LE/HF settings with a Long Pulse Width (LPW) and consisted of the following steps: 1) contact Laser lithotripsy (LE/HF/LPW dusting - 0,5 J/50 Hz or 02 J/70 Hz); 2) extraction ofmain fragments; 3) non-contact Laser lithotripsy (LE/HF/Short Pulse Width Pop Dusting - 0,5 J /80Hz). Pre-operativeand peri-operative outcomes were collected. Post-operative complications were recorded according to Clavien-Dindo Grading System. Finally, all patients under went a CT scan at three months after RIRS to assess the success of procedure, defined as stone-free or presence of ≤4 mm fragments (Clinical Insignificant Residual Fragments - CIRF). RESULTS: Overall, 104 LE/HF/LPW RIRS from December 2017 to January 2019 were performed. Mean operative time was 59 (SD ±23) minutes, median post-operative stay was two days (IQR 2-3). The post-operative complication rate was 4,8%: one patient had nausea and vomiting (Clavien-Dindo I) and four patients developed urosepsis (Clavien-Dindo II). The success rate was 88,5% (71,2% stone-free and 17,3% CIRF). CONCLUSIONS: LE/HF/LPW RIRS seems to be safe and effective in terms of positive success rate, safety and standard operative time. However, randomized clinical trials are needed to compare this technique to standard RIRS.