In recent years, with the evolution of a new generation of lasers one can operate within a large range of energy, frequency, and pulse duration settings and the miniaturization of the fibre allows for better endoscope performance, through easier deflection, and enlarges the free space in the working channel The aim of this study is to evaluate the efficiency, safety, and laser settings in laser lithotripsy using thulium fiber laser (TFL) from Quanta System during retrograde intrarenal surgery (RIRS) for stones <2cm.

A prospective randomized study with patients having renal stones of 10-20 mm and planned for RIRS was done at a single institute. A total of 200 consecutively admitted patients consenting for the procedure were included and the stones lased by either dusting or fragmentation modes. 200 µm and 150 µm laser fibers were used. Stone size, stone density, laser-on time (LOT) and laser settings, ablation speed (mm3/s), Joules/mm3 and laser power (W) values for each procedure were recorded. Stone-free rates (SFR), mean operating times, hospital stay duration, complication rates and the need for secondary procedures were assessed.

Median age of the study population ranged from 37.5 and 45 years, Median stone size was between 10.28 and 13.35 mm and median stone density was 1178 HU. Median duration of hospital stay was 2 days. Median (IQR) pulse energy was 0.6 (0.5-1.1) J. All procedures used short pulse. The median (IQR) J/mm3 was 14.9 & the median (IQR) ablation rate was 0.6 (0.2-(0.4-1.2) mm3/s. Overall complication rate was low and none related to TFL.SFRs was >95%.

TFL laser is safe and highly effective for laser lithotripsy during RIRS with excellent stone free rates and minimal morbidity.