Thulium fiber laser versus high-power holmium laser for renal stones: a systematic review and meta-analysis of high-quality studies.

BACKGROUND: Thulium fiber laser (TFL) and high-power Holmium:Yttrium-Aluminum-Garnet laser (HPHL) are common laser modalities used in flexible ureteroscopy (F-URS). Existing comparisons are imperfect due to lack of randomization, use of obsolete low-power settings, and the recent advent of technologies such as flexible and navigable ureteral access sheaths (FANS). OBJECTIVES: To compare the safety and efficacy of TFL versus HPHL for F-URS in renal stones. DESIGN: A PRISMA-compliant literature review was conducted on PubMed, EMBASE, Scopus and for randomized trials or propensity score-matched studies comparing TFL to HPHL in renal stones. DATA SOURCES AND METHODS: Primary outcomes were study-defined stone-free rate (SFR), as well as 100% SFR (zero residual fragments). Secondary outcomes were total operation time, all complications, bleeding complications, postoperative fever, and reintervention. Random-effects meta-analyses were performed to generate risk ratios (RRs) or mean differences (MDs). RESULTS: Eight studies (1290 patients) were shortlisted for analysis. Only one utilized FANS; three did not routinely use ureteral access sheaths. Between TFL and HPHL, there was no significant difference in study-reported SFR (RR = 1.17, 95% CI = 0.98-1.40, p = 0.07), 100% SFR (RR = 1.16, 95% CI = 0.90-1.50, p = 0.19), total operation time (MD -1.0 min, 95% CI = -8.8 to 6.8 min, p = 0.75), all complications (RR = 1.01, 95% CI = 0.54-1.87, p = 0.97), bleeding complications (RR = 0.59, 95%CI = 0.01-23.3, p = 0.60), postoperative fever (RR = 1.23, 95% CI = 0.68-2.24, p = 0.27), and reintervention (RR = 0.72, 95% CI = 0.38-1.34, p = 0.15). CONCLUSION: This meta-analysis of high-quality studies found no significant differences between HPHL and TFL in the trifecta of outcomes-SFR, complications, and reintervention-in F-URS for renal stones. Continued re-evaluation of this field remains a necessity as technological advancements such as FANS and novel lasers continue to emerge.