Secondary signs on preoperative CT as predictive factors for febrile urinary tract infection after ureteroscopic lithotripsy

Background: Febrile urinary tract infection (UTI) is one of the most common complications after ureteroscopic lithotripsy (URS). We evaluated the effect of secondary signs on preoperative computed tomography (CT) for febrile UTI after URS. Methods: In total, 182 patients who underwent URS for ureteral stones from January 2013 to December 2015 were retrospectively included in this study. These patients were divided into two groups according to the presence of postoperative febrile UTI after URS. We compared the clinical factors, stone factors, and secondary signs between the groups. Predictive factors for febrile UTI after URS were analyzed using a multivariate logistic regression model. Results: Febrile UTI occurred in 26 of the 182 patients. In univariate analysis, presence of comorbid chronic kidney disease (CKD) and stone size were significantly different between UTI and non-UTI groups. Among secondary signs, presence of hydroureter, perinephric fat stranding, periureteral fat stranding, and tissue rim sign were significantly different between the groups. In multivariate logistic regression analysis, comorbid CKD, stone size, perinephric fat stranding, and tissue rim sign were independent predictive factors for febrile UTI after URS. Conclusion: This study demonstrated that secondary signs including perinephric fat stranding and tissue rim sign on preoperative CT, CKD, and stone size are independent predictive factors for febrile UTI after URS.