Propensity Score Matched Analysis of Thulium Fiber vs Pulsed Thulium:Yttrium Aluminum Garnet Laser Lithotripsy in Flexible Ureteroscopy for Kidney Stone Disease Using a Flexible and Navigable Suction Ureteral Access Sheath: Results From a Prospective, Multicenter Study of the EAU Section of Endourology.

Abstract

Objective: To evaluate outcomes after flexible ureteroscopy (F-URS) for renal stone(s) using a flexible and navigable suction ureteral access sheath (FANS-UAS) comparing Thulium fiber (TFL) vs pulsed Thulium:Yttrium aluminum garnet (p-Thulium:YAG) laser.

Methods: Data from adults who had F-URS in 5 centers were prospectively collected (April 2023-January 2024). All patients had a preoperative and within 30days CT scan. Stone-free: grade A: zero fragments; grade B: single fragment ≤2mm; grade C: single fragment 2.1-4mm; grade D: single/multiple fragments >4 mm. One-to-one propensity score-matching for age, gender, prestenting, stone volume, stone location, and Hounsfield units was performed. Within 6months after surgery, an intravenous urography or CT urography scan was performed in all patients.

Results: Of 179 included patients, TFL was employed in 115 patients. After matching, 64 patients from each group with comparable baseline characteristics were included. Median lasing time was significantly longer in the TFL group (15.5 [10,23] minutes vs 13 [10,15] minutes, P=.02), while total surgical time did not differ. There was no case of blood transfusion and sepsis. Overall stone-free rate (SFR) was significantly different between the groups with a higher proportion of patients in p-Thu:YAG laser group undergoing reintervention for residual fragments (17.2% vs 3.1%). There was no case of new-onset hydronephrosis, ureteropelvic junction/ureteral stenosis, impaired urinary drainage, or altered pelvicalyceal anatomy at a median follow-up of 13weeks.

Conclusion: F-URS using FANS-UAS showed negligible serious adverse events and good SFR using both lasers. p-Thu:YAG laser showed shorter lasing time, marginal better grade A+B SFR but higher reintervention rate for residual fragments.