Mini-percutaneous nephrolithotomy versus retrograde intrarenal surgery for the treatment of 10-20 mm lower pole renal stones: a systematic review and meta-analysis.

Purpose: To compare the efficacy and safety of mini-percutaneous nephrolithotomy (mini-PCNL) versus retrograde intrarenal surgery (RIRS) for treatment of 10-20 mm lower pole renal stones.

Methods: A comprehensive literature search of PubMed, Scopus, the Cochrane Library, and Web of Science was conducted to identify all studies comparing mini-PCNL and RIRS for 10-20 mm lower pole renal stones before March 2019. Article selection proceeded according to the search strategy based on the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The meta-analysis was performed with the R program version 3.5.1.

Results: A total of five studies were included (two randomized controlled trials and three case-controlled trials) with a total of 587 patients included. The success rate was significantly higher in the mini-PCNL group (OR 1.67; 95% CI p = 0.05). Operative and fluoroscopy times were similar for both groups (MD 2.45; 95% CI p = 0.87 and MD 2.11; 95% CI p = 0.09, respectively). Concerning the hospital stay and overall complication rates, there were no differences between the two procedures (MD 41.94; 95% CI p = 0.18 and OR 1.76; 95% CI p = 0.11).

Conclusion: Our analysis showed that both procedures are safe for treatment of 10-20 mm lower pole renal stones with similar complication rates, operative times, fluoroscopy times and length of hospital stay, but mini-PCNL was significantly superior in effectiveness with a higher success rate. Based on these results, mini-PCNL may be included in the guidelines as a safe and effective alternative treatment for 10-20 mm lower pole stones.