Retrograde Intrarenal Surgery Versus Miniaturized Percutaneous Nephrolithotomy for Kidney Stones >1 cm: A Systematic Review and Meta-analysis of Randomized Trials

Abstract Context Although miniaturized percutaneous nephrolithotomy (mPCNL) and retrograde intrarenal surgery (RIRS) are both options for treating >1 cm kidney stones, controversies exist on whether one is more effective and safer than the other. Objective To systematically appraise randomized trials comparing the effectiveness and safety of mPCNL and RIRS for treating >1 cm kidney stones. Evidence acquisition A systematic search on PubMed/Medline, Web of Science, Embase, and ClinicalTrials.gov was conducted in August 2020 following the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA). Randomized trials comparing mPCNL and RIRS for >1 cm kidney stones, and reporting stone-free rate (SFR), hemoglobin drop, transfusion rate, length of hospital stay (LOS), and/or complications, were included. Evidence synthesis Eight studies compared mPCNL and RIRS, but one was not included due to its high risk of bias. SFR was higher for mPCNL (RR: 1.06 [95% coefficient interval {CI}, 1.01–1.10], p = 0.008). Hemoglobin drop was higher for mPCNL (mean difference [MD]: 0.35 [95% CI, 0.05–0.65] g/dl, p = 0.02); however, transfusion rates were similar (p = 0.44). Complication rate was similar between mPCNL and RIRS (p = 0.39), and the LOS was higher for mPCNL (MD: 1.11 [95% CI, 0.06–2.16] d, p = 0.04). A subgroup analysis of lower pole stones showed that SFR was higher for mPCNL (RR: 1.09 [95% CI, 1.00–1.19], p = 0.05). Conclusions Both approaches are effective and safe. Among these approaches, mPCNL has a higher SFR than RIRS for overall >1 cm renal and lower pole stones, but longer LOS, and a higher hemoglobin drop that does not translate into higher transfusion rates. Complications are comparable. Patient summary Randomized trials have evaluated whether miniaturized percutaneous nephrolithotomy (mPCNL) or retrograde intrarenal surgery is more effective and safer for treating >1 cm stones. After comparing the stone-free rate, hemoglobin drop, transfusion rate, length of hospital stay, and complications between both the approaches, mPCNL was found to be slightly more effective, but both were equally safe.