Introduction: Thulium fiber laser (TFL) is a new laser technology capable of pulsed laser emission, suitable for lithotripsy via photothermal and photomechanical mechanisms with 4-5x higher peak water absorption coefficient in water compared to the Ho:YAG laser. This meta-analysis aimed to compare and assess the clinical outcomes between Thulium fiber laser (TFL) and Holmium:YAG(Ho:YAG) laser lithotripsy. Methods: A systematic literature search was performed in May 2022, grey literature search in July 2022. Comparative clinical studies were evaluated according to Cochrane recommendations. Assessed outcomes include stone-free rate (SFR), complication rate, operative time (OT), laser utilization time (LUT), ablation rate (stone volume/ laser time), ablation efficiency (energy use per stone volume), total energy usage, degree of retropulsion, and hospital stay. Risk ratios (RR) and standardized mean difference (SMD) were extrapolated. Subgroup analyses, heterogeneity, publication bias, and GRADE assessment were performed. PROSPERO registration:CRD42022300788 Results: Fifteen studies with 1,698cases were included in this review. The outcome of SFR showed no significant between-group difference(RR=1.09, 95%CI 0.99, 1.20). However, subgroup analysis of TFL versus Ho:YAG with no pulse modulation showed SFR favoring TFL(RR=1.11, 95%CI 1.01, 1.23). The composite postoperative complication rate was comparable between the two intervention groups(RR0.97, 95%CI 0.66, 1.43). OT, LUT and ablation rate were significantly better for TFL than Ho:YAG(SMD-1.19, 95%CI -1.85, -0.52; SMD-1.67, 95%CI -2.62, -0.72; SMD 0.59, 95%CI 0.15, 1.03; respectively). The degree of retropulsion was significantly lower for TFL than Ho:YAG without pulse modulation(SMD-1.23, 95%CI -1.74, -0.71). Ablation efficiency, total energy usage, and hospital stay were all comparable. Based on GRADE criteria, the evidence certainty was determined to be very low. Conclusions: Overall, there was no between-group difference for SFR. However, compared to Ho:YAG with no pulse modulation, TFL renders a better SFR. Shorter operative and laser utilization times, a lesser degree of retropulsion, and a better ablation rate were noted in favor of the TFL. No overall between-group difference was noted for composite postoperative complication rate, ablation efficiency, total energy usage, and hospital stay. Currently, available clinical evidence is assessed to be of very low certainty. SOURCE OF Funding: None
