Importance
Currently available evidence for efficacy of postoperative antibiotics to prevent postoperative urinary tract infection (UTI) conflicts. Oral antibiotics rely on patient adherence and can cause unwanted systemic effects. Gentamicin is a broad-spectrum antibiotic with rapid bactericidal activity and, when administered intravesically, has no systemic absorption through intact urothelium.
Objective
We aimed to determine whether a single intravesical instillation of gentamicin at the conclusion of urogynecologic surgery would reduce the proportion of women treated for UTI within 6 weeks postoperatively compared with sham instillation.
Study Design
This was a multicenter, randomized (stratified by study site, route of prolapse repair ±suburethral sling, with balanced 1:1 randomization), participant-masked, sham-controlled, study. The primary outcome was the proportion of participants treated with antibiotics for UTI within 6 weeks postoperatively. An adjusted multivariable logistic regression model was constructed to determine predictors of postoperative UTI treatment.
Results
Three hundred seventy participants were randomized (gentamicin, 185; sham, 185), and data from 363 participants were analyzed (gentamicin, 183; sham, 180). Nineteen women in the gentamicin group and 20 women in the sham group were treated for UTI within 6 weeks postoperatively (10.4% vs 11.1%, P = 0.87). There were no adverse events related to the instillations. Increasing age (odds ratio, 1.028 [1.000–1.057]) and number of intraoperative transurethral instrumentations (odds ratio, 1.342 [1.080–1.668]) were independent predictors of postoperative UTI treatment.
Conclusions
In women undergoing urogynecologic surgery, postoperative intravesical gentamicin did not reduce the incidence of postoperative UTI. The number of intraoperative transurethral instrumentations is an important, potentially modifiable risk factor for postoperative UTI treatment.
