Comparison of the stone-free rates of mini-percutaneous nephrolithotomy, standard percutaneous nephrolithotomy, and retrograde intrarenal surgery for renal stones: A systematic review and network meta-analysis

Abstract

Background: Retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) are performed to treat renal stones. PCNL is effective for kidney stones >2 cm but is invasive compared with RIRS. Miniature PCNL (mPCNL) has been used as an alternative treatment for conventional PCNL, and employs a miniature endoscope of 11–18 Fr. We conducted a systematic review of published studies regarding the RIRS, PCNL, and mPCNL treatment modalities, and performed a network meta-analysis of the success or stone-free rates.Methods: The data collected up to January 2016 were searched using PubMed and EMBASE, and references were searched electronically. Two researchers used data extraction formats to extract data on the stone-free or success rates, study design, number of subjects and characteristics, and treatments for renal stones (i.e., RIRS, PCNL, and mPCNL). To evaluate the quality of the studies, the Downs and Black checklist, which is an observational research quality evaluation tool, was used and analyzed by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement.Results: Twenty-five studies were used to compare the stone-free or success rates of RIRS, PCNL, and mPCNL for renal stones. Six comparisons of PCNL and mPCNL, seven of mPCNL and RIRS, and 12 of RIRS and PCNL were analyzed. No difference in the stone-free rate was found between PCNL and mPCNL (OR: 0.95; 95% CI: 0.51–1.9) in network mata-analysis. Between RIRS and mPCNL, the stone-free rate of RIRS was lower than mPCNL (OR: 0.41; 95% CI: 0.021–0.82). Comparison of RIRS and PCNL revealed that RIRS was also lower than PCNL in terms of stone-free rate (OR: 0.43; 95% CI: 0.22–0.82). In the ranking analysis, rankogram showed that mPCNL was ranked as No. 1 and PCNL was ranked as No. 2. The P-score was 0.820 for mPCNL, 0.680 for PCNL and 0 for RIRS.Conclusions: PCNL and mPCNL showed higher success or stone-free rates than RIRS for the treatment of renal stones. However, PCNL and mPCNL showed no difference in the treatment outcome.

Comparison of stone clearance rate and need of nephrostomy in conventional versus mini percutaneous nephrolithotomy.

“…A comparative study of Mini-PCNL versus Conventional PCNL showed no difference in stonefree rate (SFR) 9 . Moreover, a meta-analysis by Wei Zhu and colleagues concluded that Mini-Percutaneous Nephrolithotomy resulted in less bleeding, fewer transfusions, reduced need for nephrostomy with lesser pain, and shorter hospitalization 10 .…”