Percutaneous nephrolithotomy versus retrograde intrarenal surgery: a systematic review and meta-analysis of stone-free rates and complication profiles

Abstract

Background: Nephrolithiasis is a highly prevalent urological condition, necessitating effective and minimally invasive treatment strategies. Percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS) are commonly employed for managing renal calculi, but their comparative efficacy and safety remain subjects of ongoing debate. This meta-analysis aims to synthesize current evidence, providing a comprehensive assessment of surgical outcomes between PCNL and RIRS for renal stones under 2 cm and greater than 2 cm, reported across different study designs, various surgical techniques, and different geographical distributions to guide clinical decision-making.

Methods: A systematic literature search was conducted across electronic databases, including PubMed, Embase, Scopus, Cochrane, and Clinicaltrials.gov, up to December 2024. Risk of Bias assessment was conducted using the Newcastle-Ottawa Scale for non-randomized cohort studies and the Cochrane Risk of Bias 2.0 (RoB 2.0) tool for RCTs. Data extraction focused on key outcomes such as stone-free rate, complications, operation time, hospital stay, and the need for blood transfusions. Statistical analysis utilized a random-effects model to pool data, with heterogeneity assessed using the I² statistic and publication bias evaluated via funnel plots.

Results: The analysis of 62 studies (25 were RCTs and 37 were cohorts) with 7021 patients revealed a significantly higher stone-free rate in the PCNL group compared to RIRS (RR: 1.06, 95% CI [1.04, 1.09], p < 0.00001), indicating greater efficacy in stone clearance. However, PCNL was associated with a significantly higher risk of complications (RR: 1.49, 95% CI [1.25, 1.77], p < 0.00001) and a greater need for blood transfusions (RR: 3.20, 95% CI [1.70, 6.03], p = 0.0003), associated with increased risk. Post-operative hematuria was marginally higher in the PCNL group (RR: 2.06, 95% CI [1.01, 4.19], p = 0.05). Among the PCNL techniques, all PCNL techniques showed significantly higher Hb drop; micro-PCNL was associated with the smallest hemoglobin drop relative to RIRS (MD = 0.62, 95% CI 0.38 to 0.86), followed by mini-PCNL and standard-PCNL. Operation times were comparable between the two procedures, but PCNL resulted in a significantly longer hospital stay (MD: 1.73, 95% CI [1.35, 2.10], p < 0.00001).

Conclusion: PCNL demonstrates a superior stone-free rate for renal stones under 2 cm and greater than 2 cm, but this is accompanied by a higher risk of complications and a longer hospital stay compared to RIRS. RIRS offers a safer alternative with fewer complications and shorter hospital stays, making it a viable option for at-risk patients. The use of miniaturized PCNL techniques appears to mitigate some of the complication risks associated with traditional PCNL, potentially offering a balance between efficacy and safety. Clinical decision-making should be individualized, considering patient and stone characteristics, surgeon experience, and the availability of advanced PCNL techniques.

Keywords: Kidney stones; Minimally invasive surgery; Percutaneous nephrolithotomy (PCNL); Renal stones; Retrograde intrarenal surgery (RIRS); Stone-free rate; Urolithiasis.