Recurrent urinary tract infections (rUTIs) significantly impair patient quality of life, with current treatment relying on repeated antibiotic courses for acute episodes. This approach faces challenges, including antimicrobial resistance and gut microbiome disruption. While intravesical antibiotic instillation has shown promise, its application in urostomy patients remains unexplored. We present the first description of intra-urostomy gentamicin instillation for rUTI prevention.

A 56-year-old female from Berkshire (UK) was identified with recurrent pyelonephritis UTIs on a background of a cystectomy and ileal conduit formation for interstitial cystitis. In the preceding 12 months, the patient had received 13 courses of antibiotics and required 3 hospital admissions for UTIs. Urine cultures demonstrated AmpC beta-lactamase E coli, Klebsiella, or mixed growth. 

Procedure:
A 160mg dose of gentamicin was diluted in 50ml of 0.9% sodium chloride and instilled into the ileal conduit using a Wellspect LoFric catheter. The instillation was performed with the patient in a supine position, with the aim of inducing mild flank pain during administration, suggesting reflux of the gentamicin solution into the renal pelvis. Following instillation, the patient remained supine for 20 minutes before resuming normal daily activities.

Protocol:
A 25-week regimen was implemented. Initially, 28 daily instillations were administered over a four-week induction phase. This was followed by alternate-day instillations for nine weeks. Finally, twice-weekly instillations were performed for 12 weeks.
Baseline blood tests and urine cultures were obtained. During the induction phase, blood tests and urine cultures were performed twice weekly for monitoring purposes.

The primary outcome of this study was the incidence of UTIs following intra-urostomy gentamicin. Secondary outcomes included the total antibiotic requirements post-treatment, the incidence and severity of treatment-related adverse effects, and the change in patient-reported symptom burden.

The patient successfully completed the induction phase of intra-urostomy gentamicin instillation and has transitioned to alternate-day administration. Initially, treatment was administered in the outpatient clinic by clinicians; subsequently, the patient was trained to self-administer the instillations at home.

To date, the patient has experienced no further episodes of UTIs and has not required oral or intravenous antibiotics. Transient bilateral flank pain was noted during the instillation procedure. These symptoms resolved rapidly. Pre-treatment, the patient reported chronic low-level bilateral flank pain, which has resolved.

Serial blood tests revealed no overt changes in renal function, liver function, or inflammatory markers compared to baseline. Serum gentamicin levels remained within baseline parameters throughout the induction phase. Urine cultures during the induction period showed mixed growth and one Enterococcus species. After three weeks, urine cultures demonstrated no bacterial growth for the first time.

The patient reports no adverse side effects.

We report the first documented application of intra-urostomy gentamicin instillation for the prevention of rUTIs in a patient with an ileal conduit. The patient, who had experienced a significant burden of rUTIs and associated antibiotic use, demonstrated a strong positive response to this novel treatment. Following the induction phase, the patient experienced complete resolution of UTIs, elimination of antibiotic requirements, and resolution of chronic flank pain. Serial blood tests and urine cultures confirmed the safety and efficacy of the instillation protocol, with no significant adverse effects or serum gentamicin accumulation. 

The patient successfully transitioned to self-administration at home, demonstrating the feasibility and scalability of this technique in an outpatient setting. 

Ongoing prospective follow-up will assess the patient's sustained response to intra-urostomy gentamicin instillation as she progresses through the 24-week treatment regimen, followed by post-treatment monitoring for 12 months.

These initial findings suggest that this novel approach offers a promising alternative for managing rUTIs in urostomy patients, a challenging cohort where further studies are warranted to validate these observations and establish optimal treatment strategies.