Flexible Ureteroscopy Versus Minipercutaneous Nephrolithotomy for 2 to 4 cm Renal Stones: A Systematic Review and Meta-Analysis

Abstract

Background: As the global prevalence of urolithiasis rises, selecting the optimal surgical intervention for large renal stones remains critical. Although percutaneous nephrolithotomy (PCNL) is the standard for stones more than 2 cm, the choice between flexible ureteroscopy (FURS) and mini-PCNL (mPCNL) for these burdens is debated. This systematic review and meta-analysis compares the efficacy and safety of FURS versus mPCNL for kidney stones measuring 2 to 4 cm. Methods: Following the Preferred Reporting Items of Systematic Reviews and Meta-Analysis guidelines, a comprehensive search of electronic databases identified randomized controlled trials and observational studies comparing FURS and mPCNL in adults with large renal stones of 2 to 4 cm. Primary outcomes included operative time, length of hospital stay, blood loss, hemoglobin drop, stone-free rate (SFR), and overall complication rates. Results: A total of 20 studies involving 2326 patients were included. The pooled analysis revealed no statistical significance in the overall SFR across groups between FURS and mPCNL (mean difference [MD] = 0.98, 95% confidence interval [CI] [0.95; 1.01], p < 0.1330). Conversely, FURS demonstrated a superior safety profile, with significantly shorter hospital stays (MD = −57.10, 95% CI [−84.10; −30.11], p < 0.0001), reduced hemoglobin drop (MD = −0.75, 95% CI [−1.42; −0.07], p = 0.03), and lower blood transfusion rates (risk difference [RD] −0.02, 95% CI [−0.03; −0.01], p = 0.0013). FURS was associated with a statistically significant decrease in the overall complication incidence rates (risk ratio = 0.52, 95% CI [0.41; 0.65], p < 0.0001). Conclusion: FURS is a highly effective and safer alternative to mPCNL for managing 2 to 4 cm kidney stones. Although FURS and mPCNL offer close efficacy, FURS significantly minimizes surgical morbidity and hospitalization. The integration of advanced suctioning and laser technologies further positions FURS as a competitive primary treatment for large stone burdens.