Treatment of Colovesical Fistula with Urinary Tract Infection
Surgical resection of the involved bowel segment with primary anastomosis and bladder repair is the definitive treatment for colovesical fistula, with concurrent antibiotic therapy directed at the urinary tract infection based on culture results. 1
Immediate Management of the UTI
Antibiotic Selection and Duration
- Obtain urine culture before initiating antibiotics to identify causative organisms and guide targeted therapy, as colovesical fistulas typically result in polymicrobial UTIs with bowel flora 2, 3
- Start empirical therapy with intravenous third-generation cephalosporin as first-line treatment for complicated UTI in the setting of colovesical fistula 3
- Alternative empirical regimens include amoxicillin plus an aminoglycoside, or second-generation cephalosporin plus an aminoglycoside 3
- Fluoroquinolones (ciprofloxacin 500-750 mg twice daily or levofloxacin 750 mg once daily) are appropriate if local resistance rates are below 10% and the patient has not used fluoroquinolones in the last 6 months 2, 3, 4
- Treat for 10-14 days given the complicated nature of UTI associated with fistula, as delayed response is expected 3
Critical Pitfall to Avoid
- Do not treat asymptomatic bacteriuria if present, as this only promotes resistance without clinical benefit; only treat symptomatic UTI 3
Definitive Surgical Management
Surgical Approach Selection
- One-stage surgical resection with primary anastomosis should be the preferred approach for most patients, consisting of resection of the involved bowel segment (typically sigmoid colon in diverticular disease) and primary closure of the bladder defect 1
- Laparoscopic approach is feasible and safe when performed by skilled surgeons, with lower conversion rates and similar outcomes to open surgery 1, 5
- Multi-stage procedures are reserved for patients with pelvic abscess, advanced malignancy, or previous radiation therapy 1
When Surgery Cannot Be Performed
- Defunctioning colostomy alone may be offered to improve quality of life in patients unfit for bowel resection 1
- Covered colonic self-expanding metallic stent (SEMS) can successfully seal malignant colovesical fistulas in patients requiring palliative care, avoiding colostomy and allowing fistula closure 6
- Non-surgical management is reserved only for highly selected patients who are completely unfit for any surgical intervention 1
Diagnostic Confirmation
Most Reliable Diagnostic Indicators
- Medical history revealing pneumaturia (air in urine), fecaluria (fecal matter in urine), and recurrent UTIs provides the best evidence for colovesical fistula 1, 7, 8, 5
- Cystoscopy, CT scan, and colonoscopy are only partially effective for confirming fistula presence, though CT showing intravesical gas and bladder wall thickening adjacent to colonic pathology is highly suggestive 7, 6, 5
- MRI can clearly demonstrate the fistula tract and assess inflammatory activity around the fistula, which is valuable for determining treatment approach 6
Urine Culture Patterns
- Expect polymicrobial growth with bowel organisms, most commonly Escherichia coli or mixed enteric flora 7
- Unusual organisms like Lactococcus lactis in urine culture should raise suspicion for underlying malignancy or serious pathology causing the fistula 7
Treatment Algorithm
- Confirm symptomatic UTI (not just bacteriuria) with culture
- Initiate IV third-generation cephalosporin empirically
- Perform diagnostic workup (CT, cystoscopy, colonoscopy) to confirm fistula and identify underlying cause
- Adjust antibiotics based on culture results and continue for 10-14 days
- Plan definitive one-stage laparoscopic resection with sigmoid colectomy and bladder repair for fit surgical candidates
- Consider palliative options (defunctioning stoma or covered SEMS) only for patients unfit for resection