LAUSR

OBJECTIVE To investigate the risk factors that may cause urinary tract infection (UTI) in patients applied with retrograde intrarenal surgery (RIRS). STUDY DESIGN An observational study. PLACE AND DURATION OF STUDY Departments of Urology, Ankara Training and Research Hospital, Turkey, from September 2014 to April 2017. METHODOLOGY A retrospective examination was made of patients who underwent RIRS. The patients were separated into 2 groups as those with no UTI in the postoperative period (Group 1) and those with UTI (Group 2). The groups were compared in respect of age, stone size, operating time, presence of residual stone, and body mass index. Continuous independent variables were compared using the Student's t-test and in the comparison of categorical variables, the Chisquare test was used. A value of p<0.05 was accepted as statistically significant. RESULTS Group 1 comprised 169 patients with no UTI and Group 2, 20 patients with UTI. The mean operating time was 55.82 ±14.73 minutes in Group 1 and 75.5 ±23.9 minutes in Group 2 (p=0.002). In multivariate analysis, operating time was determined as an independent prognostic risk factor increasing the risk of infection (p=0.001). The cut-off value determined with ROC analysis was 61 minutes. When operating time exceeded 61 minutes, the infection risk was increased 11.1-fold (sensitivity 75%, specificity 76%, AUC 0.76). CONCLUSION Operating time in patients applied with RIRS was determined to be an independent prognostic risk factor for UTI risk in the postoperative period. In patients where surgery lasts more than 1 hour, particular attention should be paid in respect of infection risk.