The efficacy and safety of miniaturized percutaneous nephrolithotomy versus standard percutaneous nephrolithotomy: A systematic review and meta-analysis of randomized controlled trials

Purpose: Our aim was to assess the efficacy and safety of miniaturized percutaneous nephrolithotomy (mPCNL) versus standard PCNL (sPCNL) to provide higher-level evidence.Materials and Methods: Eligible randomized controlled trials were identified from electronic databases. The data analysis was performed by the Cochrane Collaboration's software RevMan 5.3.Results: A total of 1,219 patients from 9 articles published between 2004 and 2019 were included. Compared with those who received sPCNL, patients who received mPCNL experienced a higher stone-free rate (SFR) (odds ratio [OR], 1.43; 95% confidence interval [CI], 1.03-1.99; p=0.03), lower transfusion rates (OR, 0.33; 95% CI, 0.17-0.63; p=0.0007), and lower drops in hemoglobin (mean difference [MD], -0.72; 95% CI, -1.04 to -0.40; p<0.00001), but the operative time seemed to be significantly longer (MD, 10.98; 95% CI, 3.64-18.32; p=0.003). Of note, there was no significant difference between the two groups regarding the SFR (p=0.09) for renal calculi >= 2 cm. In addition, the meta-analysis results showed no significant differences between the groups regarding urine leakage (p=0.60), postoperative fever (p=0.71), impaired ventilation (p=0.97), or total complications (p=0.29) with no heterogene- ity between trials. These results remain unaffected with regard to renal calculi >= 2 cm.Conclusions: Our findings suggested that mPCNL had a higher SFR than sPCNL and there was no significant difference between the two groups for renal stones >= 2 cm. Besides, mPCNL tended to be associated with significantly less bleeding and a lower transfusion rate, but the duration of the procedure seemed to be significantly longer.