Introduction: The new Thulium Fiber Laser (TFL) has been recently introduced as an alternative lithotripsy technology. TFL is a promising alternative to Holmium:YAG (Ho:YAG) owing to its use of a more suitable TFL wavelength, smaller fibers, and potential for using a smaller and less expensive laser system. TFL has already showed its efficacy and safety in lithotripsy. We aimed to compare between TFL and Ho:YAG ureteroscopic lithotripsy for large stones >1cm. Methods: We prospectively case controlled studied patients with ureteral calculi in the period between June 2020-July 2022. All adult patients with ureteric stones that required to undergo ureterolithotripsy were included. TFL or HO:YAG were used alternatively between the two modalities. The age, co-morbidities, body mass index (BMI), stone size, and volume were recorded. The evaluated parameters were stone-free rate (SFR), operative time, and complication rate. The surgical research section review board approved the study. Chi-Square tests with standardized residuals were calculated to see association with categorical variables and the groups. Results: A total of 172 adult patients with ureteric stones >1cm were included in this study. 87 patients in the TFL group with a mean age of 37.9+-8.8 and 85 in the Ho:YAG group with a mean age of 39.4+-10.5 (p=0.34). There was no difference regarding BMI (26+-3.6 vs 26+-3.7)(p=0.96), Co-morbidity (16% vs 24% with multiple comorbidities)(p=0.49), anaesthesia type using general or spinal (57% vs 55%) (p=0.77), stone volume (1.6+-0.5 vs 1.5+-0.5)(p=0.41), or basket use (15% vs 15%)(p=0.95). Interestingly, the TFL group took longer to perform, with higher operative time than the Ho:YAG group (81.7+-42.2 vs 67+-35.1 (p=0.016)). This was likely due to the fact the TFL group did have more multiple stones requiring lithotripsy than the Ho:YAG group, however this was not statistically significant, but clearly, clinically significant whereby there was a 27% vs 19% multiple stones rate (p=0.23). There was no difference in the SFR (95% vs 96% (p=0.72)), second look ureteroscopy (14% vs 8%) (p=0.25)) or early or late complication rates, 1% vs 4% (p=0.3) and 0% vs. 1% (p=0.31), respectively. All patients were stone and complication free on follow up. Conclusions: TFL has proven its efficacy and safety with high SFR and low early and late complication rates. TFL ureteroscopic lithotripsy took longer to perform than Ho:YAG, probably due to having a higher stone burden, however statistically not significant. SOURCE OF Funding: No funding for this review was received.
