Association between Preoperative Urine Culture and Urinary Tract Infection after Spinal Surgery

STUDY DESIGN: This is a retrospective study. PURPOSE: This study assessed risk factors accounting for urinary tract infections (UTIs) to determine whether preoperative asymptomatic UTI (aUTI) could be used to predict UTIs in patients after spinal surgery. OVERVIEW OF LITERATURE: UTI is a spinal surgery complication that increases the incidence of surgical site infections. However, the risk factors for UTIs after spinal surgery remain unclear. METHODS: This study included 509 (mean age, 54.5 years; 239 males and 270 females) patients who underwent posterior spine surgery at the department of the current study. First, clean catch urine was collected, after which a urine culture was performed for all patients before surgery. Preoperative detection of the aUTI (>105 colony-forming units/mL) rate was then determined. Subsequently, risk factors for postoperative UTI were evaluated using logistic regression analysis with the following as independent variables: age, sex, obesity, diabetes, spinal cord tumor, the preoperative Japanese Orthopedic Association (JOA) score, JOA-bladder function, preoperative urine culture positivity, aUTI, preoperative Escherichia coli detection, the postoperative catheter placement period, instrumentation, number of surgical levels, surgery duration, and blood loss. RESULTS: The preoperative aUTI and postoperative UTI incidences were 8.1% and 4.1%, respectively. Furthermore, multivariate logistic analysis showed that the risk factor for postoperative UTI was preoperative aUTI (odds ratio, 4.234; 95% confidence interval, 1.532–11.702; p=0.005). CONCLUSIONS: Preoperative aUTI is a risk factor for UTI in patients after spinal surgery.