The clinical efficiency and safety of 60W superpulse thulium fiber laser in retrograde intrarenal surgery

INTRODUCTION: Our aim is to evaluate the clinical efficiency and safety of 60W Thulium fiber laser (TFL) during retrograde intrarenal surgery (RIRS). The performance of the TFL across different ranges of stone volumes and stone densities is assessed. MATERIALS AND METHODS: Between October 2019 and August 2020, a prospective study was done on 135 patients with < 20 mm renal stones, who underwent RIRS using TFL. Stone parameters, total laser time, total energy delivered (kJ), and fiber burn-back were recorded. Laser efficacy (J/mm(3)) and ablation speed (mm(3)/s) were calculated. RESULTS: Data of 126 of 135 patients included in the study were analyzed. The mean patient age was 45.04 ± 12.30 years. Mean stone size was 15.19 ± 4.52 mm, and mean stone volume was 1061.85 ± 806.81 mm(3). Mean laser time was 19.78 ± 12.32 min. At higher stone volume (>1000 mm(3)), J/mm(3) decreased significantly from 16.18 ± 5.90 to 10.92 ± 3.21 (P < 0.001) and the ablation speed increased significantly (0.77 ± 0.28–1.04 ± 0.28 mm(3)/s [P < 0.001]). Stone density did not have a significant influence on the laser efficacy [B = -0.31 (-2.45 to 1.82, p=0.771)] or on the ablation speed [B = -0.06 (-0.17 to 0.05, p=0.278)]. Overall SFR was 93.6%. The complication rate was 16.6% (21/126). Out of the 21, 12 patients had hematuria and 9 had fever, which were of Clavien grades 1–2. CONCLUSION: Superpulse TFL is efficient and safe. The work efficiency increases for larger volume stones. The work efficiency remains the same across different stone densities. No complication more than Clavien grade 2 was encountered.