Intrarenal Antibiotic Irrigation During Percutaneous Nephrolithotomy Reduces Postoperative Infections and Eliminates Sepsis in High-Risk Patients: A Matched Cohort Study.

PURPOSE: To evaluate whether intrarenal antibiotic-augmented irrigation with neomycin/polymyxin B during percutaneous nephrolithotomy (PCNL) in patients at high risk for infection was associated with lower postoperative infectious complications and reduced infection-related resource utilization. MATERIALS AND METHODS: We performed a single-center, retrospective matched cohort study of adults undergoing PCNL who were at high risk for infection between January 2020 and December 2024. Fifty patients who received intrarenal neomycin/polymyxin B irrigation (1 mL GU irrigant per 3-L saline bag) were matched 1:1 to controls receiving standard saline irrigation by age, sex, diabetes, Charlson Comorbidity Index, and preoperative urinary drainage. The primary end-point was symptomatic urinary tract infection (UTI) within 30 days. Secondary outcomes included systemic inflammatory response syndrome (SIRS), sepsis during index hospitalization, infection-related prolonged hospitalization, emergency department visits for infection, and 30-day infection-related readmission. RESULTS: Thirty-day UTI occurred in 3/50 patients (6.0%) in the GU group vs 17/50 (34.0%) in controls (number needed to treat 3.6; p = 0.001). SIRS occurred in 16.0% vs 48.0% (p = 0.001), sepsis during index hospitalization in 0% vs 16.0% (p = 0.006), and infection-related prolonged hospitalization in 0% vs 20.0% (p = 0.001). In adjusted analysis (n = 99), GU irrigation remained independently associated with lower 30-day UTI risk (adjusted OR 0.11, 95% CI 0.03-0.44; p = 0.002). Short-term renal safety outcomes were comparable between groups. Modeled economic analysis suggested potential net savings of approximately $7800 per patient. CONCLUSIONS: In this matched cohort of PCNL patients at high risk for infection, intrarenal neomycin/polymyxin B irrigation was associated with substantially lower postoperative infectious morbidity, including elimination of sepsis during index hospitalization, with comparable short-term renal safety outcomes.