Risk factors of febrile urinary tract infections following retrograde intrarenal surgery for renal stones

We aimed to evaluate the risk factors of febrile urinary tract infection (UTI) following retrograde intrarenal surgery (RIRS) for treating renal stones. We retrospectively reviewed the data of patients with 10 - 30 mm kidney stones who underwent RIRS from January 2014 to July 2017. Evaluation included age, gender, body mass index, stone size, stone location, and operative time. All surgeries were performed by a single surgeon and ureteral stenting was not done prior surgery. The risk factors of febrile UTI after RIRS were assessed by univariate and multivariate logistic regression analysis. A total of 150 patients were included in the present study, and 17 patients (11.3%) had febrile UTI after RIRS. Mean patient age was 56.64 +/- 13.91 years, and both genders were evenly distributed. Mean stone size was 14.16 +/- 5.89 mm. and mean operation time was 74.50 +/- 42.56 minutes. According to univariate analysis, preoperative pyuria was associated with postoperative febrile UTI. Multivariate logistic regression analysis showed that preoperative pyuria was the only independent risk factor of infectious complications after RIRS (odds ratios 8.311, 95% confidence intervals 1.759 - 39.275, P = .008). Age, gender, body mass index, comorbidity, preoperative bacteriuria, presence of hydronephrosis, renal stone characteristics, and operative time were not associated with febrile UTI after RIRS. Preoperative pyuria was the only risk factor of infectious complications following RIRS. Therefore, careful management after RIRS is necessary especially when preoperative urinalysis shows pyuria.