Intravesical gentamicin instillation in the prevention of recurrent urinary tract infections in children with neurogenic bladder- a single-center retrospective observational study

Abstract

Recurrent urinary tract infections (UTI) in children with neurogenic bladder (NGB) put them at high risk of morbidity and mortality from urosepsis and end-stage renal disease (ESRD). Since the efficacy of low-dose prophylactic antibiotics to prevent these recurrences has been declining since the emergence of extended-spectrum beta-lactamase (ESBL) organisms, intravesical gentamicin instillation has also been used, but only scarce data in children is available in the literature. We evaluate the efficacy of intravesical gentamicin instillation to reduce UTIs in children with NGB, compare it with oral antibiotic prophylaxis and determine its effect on pathogens resistance to antibiotics. Retrospective observational study of 17 children with NGB managed in a tertiary center. Intravesical gentamicin instillation followed an initial period of oral antibiotic prophylaxis. In a conditional negative binomial regression model, a matched comparison of the rate of UTIs, the identified pathogens and their antibiotics susceptibility between the two therapies was performed for each individual child, RESULTS: When compared to antibiotic prophylaxis, intravesical gentamicin instillation showed no significant difference in the yearly rate of UTI, symptomatic UTI, or admissions for intravenous antibiotic therapy. However, it was associated with a 38% reduction in the incidence rate ratio of UTI (p=0.04) and 75% of asymptomatic UTI (p=0.006) After intravesical gentamicin instillation, five children (31%) had a gentamicin-resistant UTI, similar to before that treatment (p=0.76). Although the overall rate of UTI and of asymptomatic infections were significantly lower with intravesical gentamicin instillation than during oral antibiotic therapy, there was no significant difference in the rate of symptomatic UTIs or UTIs requiring admissions, probably because of the small sample size. In addition, neither an emergence of ESBL pathogens nor the rate of pathogens resistance to gentamicin was observed with intravesical gentamicin instillation. As to the potential nephrotoxicity of aminoglycosides, the calculated GFR for all children remained normal. Strengths of our study include the use of a matched paired comparison of each participant with him/herself with each treatment modality, thus eliminating potential confounding by some individual characteristics. In addition, and unlike previous studies, we have also used a robust multivariate statistical analysis to compare counts and rates of outcomes. Limitations include the absence of gentamicin serum levels monitoring, of hearing testing, and also the small sample size. Intravesical gentamicin instillation decreases the overall rate of UTI and asymptomatic infections in children with NGB without increasing the rate of bacterial resistance to gentamicin.