Risk Factors for Urinary Tract Infection following Mid Urethral Sling Surgery

Mid urethral sling surgery is common. Postoperative urinary tract infection rates vary in the literature and independent risk factors for urinary tract infection are not well defined. We sought to determine the incidence of and risk factors for urinary tract infection following mid urethral sling surgery.

A retrospective cohort of females who underwent sling surgery was captured from the 2006 to 2014 NSQIP® (National Surgical Quality Improvement Program®) database. Exclusion criteria included male gender, nonelective surgery, totally dependent functional status, preoperative infection, prior surgery within 30 days, ASA® (American Society of Anesthesiologists®) Physical Status Classification 4 or greater, concomitant procedure and operative time greater than 60 minutes. The primary outcome was the incidence of urinary tract infection within 30 days of mid urethral sling surgery. Risk factors for urinary tract infection were assessed by examining patient demographic, comorbidity and surgical variables. Logistic regression analyses were performed to estimate the ORs of individual risk factors. Multivariable logistic regression was then performed to adjust for confounding.

A total of 9,022 mid urethral sling surgeries were identified. The urinary tract infection incidence was 2.6%. Factors independently associated with an increased infection risk included age greater than 65 years (OR 1.54, 95% CI 1.07-2.22), body mass index greater than 40 kg/m² (OR 1.89, 95% CI 1.23-2.92) and hospital admission (OR 2.06, 95% CI 1.37-3.11). Mid urethral sling surgery performed by urologists carried a reduced risk of infection compared to the surgery done by gynecologists (OR 0.52, 95% CI 0.40-0.69).

The urinary tract infection risk following mid urethral sling surgery in NSQIP associated hospitals is low. Novel patient and surgical factors for postoperative urinary tract infection have been identified and merit further study.