A new study published in the Journal of Urogynecology suggests that postoperative intravesical gentamicin did not lower the incidence of postoperative urinary tract infection (UTI) in women after urogynecologic surgery.
There is conflicting data about the effectiveness of postoperative antibiotics in preventing postoperative urinary tract infections. Oral antibiotics can have unintended systemic effects and depend on patient adherence. When injected intravesically, the broad-spectrum antibiotic gentamicin shows fast bactericidal action and little systemic absorption due to intact urothelium.

In order to find out if a single intravesical instillation of gentamicin at the completion of urogynecologic surgery would decrease the proportion of women treated for UTI within 6 weeks postoperatively compared with sham instillation, Mary M. Rieger and colleagues conducted this study.
This was a randomized, multicenter, participant-masked, sham-controlled trial that was stratified by study location, prolapse repair method (suburethral sling), and balanced 1:1 randomization. The proportion of individuals who received antibiotic treatment for a UTI within six weeks following surgery was the main result. To identify determinants of postoperative UTI therapy, an adjusted multivariable logistic regression model was created.
The key findings of this study were:
1. Gentamicin (185 participants) and sham (185 participants) were randomly assigned to 370 individuals, and 363 participants' data were evaluated (gentamicin, 183; sham, 180).
2. Within 6 weeks following surgery, 19 women in the gentamicin group and 20 women in the control group received treatment for UTI (10.4% vs. 11.1%, P = 0.87).
3. There were no negative side effects from the installations.
4. Growing older and the quantity of intraoperative transurethral instruments were independent predictors of postoperative UTI therapy.
In conclusion, the percentage of women who go on to suffer urinary tract infections is not significantly decreased by posturogynecological intravesical gentamicin treatment. With each operation increasing the risk of a postoperative UTI by 34%, the number of transurethral instrumentation (such as cystoscopy or catheterization) procedures performed after surgery is crucial.
Reference:
Rieger, M. M., Shah, N. M., Ferrante, K. L., Tan-Kim, J., Jacobs, M. B., Brubaker, L., & Alperin, M. (2022). Intraoperative Gentamicin Intravesical Instillation for Prevention of Urinary Tract Infection After Urogynecologic Surgery: A Randomized Controlled Trial. Urogynecology (Hagerstown, Md.), 28(12), 825–833. https://doi.org/10.1097/SPV.0000000000001233