Bacteriological safety and cost-effectiveness of a nonrefluxing valve in the irrigation system during outpatient flexible cystoscopy

Abstract

Objective: To critically evaluate the infection rate associated with the use of a nonrefluxing irrigation system for outpatient flexible cystoscopy, by comparing it with conventional irrigation systems, and to determine the costs and benefits of this system of irrigation delivery. Patients and methods: All patients undergoing flexible cystoscopy on scheduled outpatient lists were considered for inclusion in the study; 143 patients of 220 undergoing cystoscopy fulfilled the study criteria. The study group of patients underwent cystoscopy with a new single-use nonrefluxing valve inserted into the same irrigation delivery system that was used for the whole endoscopy session, and the control group had the complete irrigation system changed after each endoscopic examination. Midstream urine samples were taken for analysis before cystoscopy and again 3-4 days later. Infection was defined as a pure growth of ≥ 105 organisms/mL, with associated pyuria defined as ≥ 10 pus cells per high power microscopic field. Results: Complete data were available on 133 patients, with a further nine being excluded from the statistical analysis because they had a pre-existing urinary tract infection, leaving 64 patients in the study and 69 in the control groups. The overall infection rate for flexible cystoscopy was 3.2%, with no significant difference between the study and control groups. Cost savings of > 35% can be expected using the nonrefluxing valve method of irrigation delivery. Conclusion: The nonrefluxing valve caused no detectable increase in patient morbidity from bacterial infection when compared with conventional irrigation systems for flexible cystoscopy, and can save considerable costs.