Prospective Randomized Controlled Trial to Compare Dusting vs Fragmentation Using Thulium Fiber Laser in Retrograde Intrarenal Surgery.

ABSTRACT

Objective: To compare the dusting vs fragmentation modes with thulium fiber laser (TFL) in retrograde intrarenal surgery (RIRS) for upper tract stones using the same fixed low-power settings in both the arms. The primary objective was to compare the stone-free rate (SFR) and secondary objectives were to compare mean operating times, hospital stay duration, complication rates, need for secondary procedures, and laser efficacy. Materials and Methods: A prospective randomized trial, with patients having proximal ureteral or renal stones of 10-20 mm and planned for RIRS was done at a single institute. A total of 60 consecutively admitted patients with signed consent were included for randomization with 30 patients in each arm of dusting and fragmentation modes. Results: Median age in dusting and fragmentation arms of 41.5 and 45.5 years, median stone size of 10.45 and 12.25 mm, median stone volume of 351.6 and 490.7 mm3, and median stone density of 1263.5 HU in both arms with comparable hospital stay of median of 2 days in both arms. Lasing time was significantly lesser in the fragmentation group (20.5 minutes; interquartile range [IQR] 15.12-31.62) than in the dusting group (34.25 minutes, IQR 26.62-38.62, p < 0.001). Higher ablation speed for fragmentation mode (0.405 mm3/sec, IQR 0.337-0.635) than for dusting mode (0.17 mm3/sec, IQR 0.135-0.325, p < 0.001). SFRs and complication rates were comparable in both the arms. Conclusion: TFL in fragmentation mode has shorter lasing times and better laser efficacy than dusting mode with comparable minimal complications, SFRs, and hospital stay duration. Clinical Trial Registration number CTRI050827.