Standard versus mini-percutaneous nephrolithotomy for renal stones: a meta-analysis

Objectives: To compare the standard percutaneous nephrolithotomy and mini-percutaneous nephrolithotomy in order to determine the optimal tract size for patients with renal stones.

Methods: A systematic search of Web of Science, EMBASE, Cochrane Library, and PubMed databases was conducted for articles published through 20 August 2019, reporting on a comparison of the standard percutaneous nephrolithotomy and mini-percutaneous nephrolithotomy using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

Results: Of 763 studies, 14 were considered for the evidence synthesis. A total of 1980 cases were included. Of these patients, 897 cases underwent standard percutaneous nephrolithotomy, and 1083 cases underwent mini-percutaneous nephrolithotomy. Stone-free rates were 87.6% (786 of 897 patients) for standard percutaneous nephrolithotomy and 87.8% (951 of 1083 patients) for mini-percutaneous nephrolithotomy (p = 0.57). Tract sizes of 30F and 22-26F in standard percutaneous nephrolithotomy group shorten operation time compared with mini-percutaneous nephrolithotomy (p = 0.02; p = 0.004; respectively). Leakage (p = 0.04), bleeding (p = 0.01), blood transfusion (p < 0.00001), and renal pelvis perforation (p = 0.02) were more common in standard percutaneous nephrolithotomy group than in mini-percutaneous nephrolithotomy group. Subgroup analysis showed only blood transfusion for 30F and 22-26F standard percutaneous nephrolithotomy group was more common than mini-percutaneous nephrolithotomy (p < 0.0001, p = 0.005, respectively).

Conclusions: Standard percutaneous nephrolithotomy was associated with higher leakage, bleeding, blood transfusion, and renal pelvis perforation, but had a shorter operation time. Tract size of 30F improved the stone-free rate compared with mini-percutaneous nephrolithotomy, but led to more complications. Tract size of 22-26F was no better than 30F or mini-percutaneous nephrolithotomy.