Assessing the Optimal Urine Culture for Predicting Systemic Inflammatory Response Syndrome After Percutaneous Nephrolithotomy and Retrograde Intrarenal Surgery: Results from a Systematic Review and Meta-Analysis

Background: Systemic inflammatory response syndrome (SIRS) is a dangerous complication after percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS). We aimed to review the diagnostic accuracy of midstream urine culture (MSUC), pelvic urine culture (PUC), and stone culture (SC) derived from the same cases to predict SIRS after PCNL and/or RIRS. Materials and Methods: A comprehensive literature search was performed, using MEDLINE, EMBASE, and Cochrane Central Controlled Register of Trials. Sensitivity and specificity were calculated for MSUC, PUC, and SC. The diagnostic odds ratio (DOR) was estimated for each study with a random effect and hierarchical summary receiver operating characteristic (HSROC) model leading to a corresponding 95% confidence interval (CI). Overall test accuracy was measured by finding the area under the curve (AUC). An AUC value >0.70 stands for adequate overall accuracy. Results: The search retrieved 537 articles. After screening, 21 studies involving 5238 patients were included for the meta-analysis. The pooled sensitivity for MSUC was 0.322 (95% CI 0.2228–0.432), and pooled specificity 0.854 (95% CI 0.810–0.889). The DOR was low at 2.780 (95% CI 1.769–4.368), showing poor overall diagnostic accuracy. The pooled sensitivity for PUC was 0.323 (95% CI 0.224–0.440) and specificity 0.931 (95% CI 0.896–0.954). The DOR was 6.377 (95% CI 4.065–10.004), showing a mild overall diagnostic accuracy. The pooled sensitivity for SC was 0.552 (95% CI 0.441–0.658) and specificity 0.847 (95% CI 0.798–0.886). The DOR was 6.820 (95% CI 4.435–10.488), showing mild overall diagnostic accuracy. The AUC for HSROC for MSUC was 0.65, 0.73, and 0.75 for PUC and SC, respectively. Conclusion: MSUC is a poor predictor for postoperative SIRS. PUC or SC should be collected during lithotripsy to better predict the possibility of developing postoperative SIRS after PCNL and RIRS.