Post-Ureteroscopy (URS) infectious complications in high-risk patients:Insights from England National database (NHS) of 79,676 cases

Introduction & Objectives: This study aimed to determine the proportion of patients undergoing ureteroscopy (URS) for urolithiasis within the English National Health Service (NHS) who are at risk of adverse outcomes, and to assess the association between predefined risk factors and major postoperative complications. Materials & Methods: This retrospective study used UK HES data to identify all patients undergoing URS for urolithiasis in NHS (2018-2023). Patients were stratified into 18 cohorts based on demographics, comorbidities, infection history, and procedural factors. Eleven postoperative outcomes were assessed, including pain, dysuria, mechanical complications, renal failure, UTI, sepsis, readmissions (1–30, 31–60, 61–90 days), critical care admission, and 90-day all-cause mortality. Cohort definitions and outcomes were based on the 2025 Delphi consensus (Somani et al., 2025). HES includes only confirmed diagnoses from hospital attendances and data not captured in HES were excluded. Data use was approved under NHS Digital agreement DARS-NIC-05934-M7V9K for epidemiological research. Results: A total of 79,676 patients were included. The overall postoperative pain rate was 8%, rising to 12% in females and 9% in patients who experienced complications (P <0.001). UTI incidence was significantly higher among females (33.8% vs 16.0% in males), patients aged ≥70 years (34.1% vs 19.2%), and those with comorbidities (35.6% vs 12.3%) (P <0.001). Sepsis rates were also significantly elevated in females (14.8% vs 7.2% in males), older patients (17.5% in ≥70 vs 7.8% in <70 years), and those with comorbidities (18.2% vs 3.6% without) (P <0.001). The highest sepsis rates were observed in patients with recent sepsis (96.8%), prior UTI (50.0%), diabetes with complications (29.1%), immunosuppression (30.0%), and a Charlson Comorbidity Index (CCI) ≥7 (21.6%) (P <0.001). Admission to critical care was high in patients with prior sepsis, prior UTI, immunosuppression, diabetes with complications, ischaemic heart disease, and Charlson Comorbidity Index (CCI) ≥7. Conclusions: This nationwide analysis confirms that high-risk patients experience significantly higher complication rates following URS. Optimising preoperative patient selection is essential, and strategies to limit intrarenal pressure may help mitigate adverse events. Further ;81(S2 )International Conference on Endourology research is needed to inform preventive measures and enhance patient outcomes. ;81(S2 )