Evaluation of the Safety and Efficacy of Thulium Fiber Laser Lithotripsy for Ureteric Stones During Semi-rigid Ureteroscopy

Introduction: Semi-rigid ureteroscopy is commonly performed to manage ureteric stones, and thulium fiber laser (TFL) has emerged as the preferred modality for stone lithotripsy. We evaluated the safety and efficacy of TFL in the ureter during treatment of ureteric calculi. Methods: We retrospectively evaluated 124 consecutive patients who underwent TFL lithotripsy for ureteric stones during semi-rigid ureteroscopy. Preoperatively, the patients were evaluated using urine culture and non-contrast computed tomography. The stone size, volume, and Hounsfield units (HU) were recorded. Intraoperative parameters, including visibility, bleeding, and stone retropulsion, were assessed. Postoperative complications such as hematuria, fever, sepsis, and residual stones were evaluated. The stone-free rate was assessed using ultrasonography and kidney, ureter, and bladder (KUB) radiography. Results: Mean stone size, volume, and HU were 10.2 mm, 237.7 mm3, and 962, respectively. The total power was 6 watts for the majority of the patients. Bleeding was observed in two (1.61%) patients; vision was rated as good in 94 (75.8%) cases, and stone retropulsion occurred in four (3.22%) patients. Stone ablation efficacy and ablation speed were 9.32 J/mm3 and 0.23 mm3/s, respectively. Satava complications were Grade I in two (1.16%) patients, Grade IIa in four (3.22%) patients, and Grade IIb in one (0.80%) patient. According to the Clavien-Dindo classification, complications were Grade I in 12 (9.67%) patients, Grade II in three (2.41%) patients, and Grade III in one (1.61%) patient. The stone-free rate was 98%. During follow-up, a ureteric stricture was observed in one (0.80) patient. Conclusions: The present study suggests that the use of TFL in fragmentation mode, with a power setting of 6 watts and not exceeding 10 watts, is effective. TFL is a safe and effective treatment modality for ureteral laser lithotripsy.