Minimally invasive nephrolithotomy versus retrograde intrarenal surgery in surgical management of Lower calyceal stones: A systematic review with meta-analysis.

Abstract

The efficacy and safety of minimally invasive nephrolithotomy (MPCNL) versus retrograde intrarenal surgery (RIRS) was assessed for lower calyceal (LC) stones. Our team conducted a systematic literature search up to December, 2022, using PUBMED, EMBASE and the Cochrane Library. The study was registered in PROSPERO, CRD 42021247197. Randomized controlled trials evaluating the efficacy and safety of MPCNL versus RIRS for LC stones were collected. Heterogeneity among the studies was assessed using the χ2 test based on the Q and I2 tests. Pooled effect sizes were calculated using a fixed model if I2 < 50%; otherwise, a random-effects model was chosen. The primary outcomes were the 3-month stone-free rate (3SFR) and total complications, while the secondary outcomes were the operating time, hospital stay, hemoglobin reduction, bleeding, postoperative fever and complications with the Clavien-Dindo system. A subgroup analysis of 10-20mm LC stones was also designed. A total of 7 peer-reviewed trials comprising 711 patients were identified. No statistical differences were observed in the heterogeneity results of the 3SFR or total complications (P>0.1, I2 < 50%). Compared with RIRS, MPCNL had an unfavorable safety profile, resulting in total complications (OR: 1.87 [95%CI: 1.05, 3.33]; P=0.03), hemoglobin reduction (OR: 0.81 [95%CI: 0.15, 1.47]; P=0.02) and complications with Grade I (OR: 5.52 [95%CI: 1.34, 22.83]; P=0.02) but an improved efficacy and 3SFR (OR: 2.43 [95%CI: 1.48, 3.97]; P=0.0004). As for the 10-20mm LC stones, compared with RIRS, MPCNL also had an unfavorable safety profile, resulting in total complications (OR: 2.47 [95%CI: 1.20, 5.07]; P=0.01), complications with Grade I (OR: 4.97 [95%CI: 0.99, 25.01]; P=0.05) and an increased hospital stay (OR: 2.46 [95%CI: 2.26, 2.66]; P=0.00001) but an improved efficacy and 3SFR (OR: 3.10 [95%CI: 1.61, 5.99]; P=0.0008). The efficacy effect of MPCNL and safety effect of RIRS were nearly equal for both stones sized < 20mm (NNT = 17, NNH = 20) and stones sized 10-20mm (NNT = 20, NNH = 13). No statistical difference was found between the MPCNL and RIRS groups for the rest of outcomes. Both MPCNL and RIRS are safe and effective management methods. Moreover, compared with RIRS, MPCNL had an unfavorable safety profile but improved efficacy for LC stones of ≤20mm or 10-20mm, and the differences were statistically significant. The relative profit of efficacy of MPCNL was similar to the relative profit of safety of RIRS.