To evaluate the clinical performance of the SOLTIVE SuperPulsed thulium fiber laser (TFL) compared to pulse-modulated Holmium:YAG (HoYAG) in flexible ureteroscopy for renal stones <2 cm, with a focus on efficiency, ergonomics, and surgeon experience, given the limited comparative U.S. clinical data.

We performed a single-center prospective randomized controlled trial (September, 2022-September, 2024) of patients ≥18 years with stone burden < 2 cm undergoing ureteroscopic lithotripsy. Participants were randomized 1:1 to SOLTIVE TFL or pulse-modulated HoYAG (Lumenis Pulse 120 H with MOSES 2.0). The primary endpoint was zero stone-free rate (SFR) on postoperative CT. Secondary endpoints included operative metrics, reintervention, fiber degradation, and surgeon-reported satisfaction and noise encumbrance. Statistical significance was set at P < .05.

Eighty-three patients were analyzed (HoYAG: 47; TFL: 36). Groups were similar in demographics, stone characteristics, and operative time. SFRs were comparable (Zero-SFR: 51.3% vs 53.6%, P = 1.00; < 2 mm: 66.7% vs 85.7%, P = .14; < 4 mm: 82.1% vs 89.3%, P = .50). Fiber degradation was significantly lower with TFL (2.8% vs 21.3%, P = .02). Surgeon satisfaction favored TFL for handling, maneuverability, and dusting performance (all P < .001). TFL also yielded lower reported noise encumbrance across all measures ( P < .001).

While SFR was equivalent, SOLTIVE TFL showed clear benefits in fiber durability, surgeon satisfaction, and intraoperative noise profile compared to high-power pulse-modulated HoYAG. These results support TFL as a preferred flexible ureteroscopy platform. Multicenter trials are needed to confirm generalizability.