To compare the surgical outcomes between nonreduction and reduction pyeloplasty in the management of ureteropelvic junction obstruction among patients such as postoperative functional outcomes, complication rate, and failure rate through a meta-analysis of comparative studies.

Electronic databases including PubMed, EMBASE, Scopus, and Cochrane Library, including the Cochrane Database of Systematic Reviews and the Cochrane Central Register of Controlled Trials were searched to identify published literature comparing reduction and nonreduction pyeloplasty in adult and pediatric patients. Data on anteroposterior pelvic diameter, differential renal function, and complications were extracted. Data synthesis and statistical analysis were done using ReviewManager. Random-effects model and standard mean difference were used for calculation of all effect estimates with 95% confidence intervals for extrapolation. This study was registered with PROSPERO (CRD42021288645).

Five studies were selected for analysis, encompassing 177 renal units, of which 88 cases were reduction pyeloplasty and 89 cases were nonreduction pyeloplasty. Continuous variables were presented as standard mean differences with their 95% confidence intervals. Our overall pooled effect estimates show a statistically significant difference favoring reduction pyeloplasty in terms of postoperative anteroposterior pelvic diameter (SMD=1.77; 95%CI 0.43, 3.10) and change in APPD (SMD=1.21; 95%CI 0.07, 2.36). No statistically significant difference was observed for postoperative differential renal function (SMD=0.27; 95%CI -0.10, 0.64) and change in DRF (SMD=0.68; 95%CI -0.39, 1.74). Subgroup analyses revealed no statistically significant difference for all functional outcomes. Analysis of both groups revealed no significant difference in terms of postoperative complication rate (RR=0.91; 95%CI 0.38, 2.16) and failure rate (RR=1.50; 95%CI 0.28, 8.04).

The evidence suggests that nonreduction pyeloplasty results in comparable postoperative DRF and change in DRF. Although reduction pyeloplasty results in superior APPD and change in APPD compared to nonreduction pyeloplasty, these findings may be clinically negligible. Complication and failure rates between the two groups are comparable.