Urinary Fistula
This booklet is intended as a practical guide to patient care for registrars, medical officers, interns and medical students attached to the gynaecology units at the University of the Witwatersrand Academic Hospitals. Anyone can use it.
Fistula following childbirth or surgery
Fistula caused by cervical malignancy
Fistula caused by radiotherapy
The most common is vesicovaginal fistula (VVF). Fistulae present with continuous incontinence of urine. The common causes are:
- Obstetric (obstructed labour)
- Post-surgical (caesarean section, hysterectomy)
- Malignancy (cervical cancer)
- Radiation (treatment for cervical cancer)
FISTULA FOLLOWING CHILDBIRTH OR SURGERY
Clinical assessment
- Establish the events that preceded & caused the fistula
- General, abdominal & vaginal examination
- Speculum examination, & look for leakage of urine by asking the patient to cough while withdrawing the speculum
- Fistulae are not always easily palpable or visible on examination
- Exclude other causes of ‘continuous incontinence’:
- Stress incontinence – urine leaks from the urethra with pressure
- Watery discharge – infection or granulations after hysterectomy
Investigations
- Urine MC&S – infection is unusual with a fistula
- Three-swab test with methylene blue
- Intravenous pyelogram (IVP) – to show site of fistula & state of ureters
- Voiding cysto-urethrogram (VCU) – to show site of fistulae
- Cystoscopy
Three-swab test
Inject 2ml methylene blue into 1L N/saline. Insert a Foley catheter into the patient’s bladder & empty the bladder if necessary. Insert 3 swabs into her vagina. Run the methylene blue solution into the bladder. The patient will tolerate about 200ml. Ask the patient to stand up & walk around for 2 minutes, then remove the three swabs. Always count the swabs after removal.
- If the upper swab only is stained with yellow urine, the fistula is uretero-vaginal
- If the middle or upper swab is stained blue, the fistula is vesicovaginal
- If the lower swab only is stained blue, there may be stress incontinence or no fistula, but leakage around the catheter
Surgery
- Cystoscopy may precede surgery. The approach may be abdominal or vaginal or combined
- The method of fistula repair will depend on the nature of the fistula as defined clinically & on investigation. In summary the fistula is excised & the layers of the defect closed separately –Latzko technique. A graft may be used for larger fistulae – omentum, or labia majora swung graft (Martius graft)
- Consult a gynaecologist or urologist experienced with management of fistulae
- Obstetric fistula repair should be delayed for 2-3 months after delivery
- Post-surgical fistulae may be repaired as soon as they are recognized
FISTULA CAUSED BY CERVICAL MALIGNANCY
Patients have advanced stage malignancy, & may not be fit for surgery.
Assessment
- History and full clinical examination
- Search for metastases & other manifestations of malignancy
- Work up fully for cervical cancer, including biopsy, if not already done (Cervical Screening).
- Consider pain relief, nutrition, & quality of life issues
Management
- The definitive treatment is urinary diversion, e.g. ileal conduit
- Discuss with an experienced consultant
- Consult urologists for diversion if the patient agrees & prognosis allows
- Continue usual care (radiotherapy, pain relief etc.)
FISTULA CAUSED BY RADIOTHERAPY
It is important to determine if the fistula is caused by radiation or by a cancer recurrence
Assessment
- Take a complete history & do a full clinical examination
- Search for metastases & other manifestations of malignancy
- Vaginal & speculum examination may be painful & difficult
- Biopsy from the edge of the fistula if possible
- FBC, U&E, HIV & CD4 count, chest x-ray; consider IVP & cystoscopy with biopsy.
Management
- Discuss with an experienced consultant
- Report the fistula to the radiotherapy department (Johannesburg Hospital)
- Consult urologists for urinary diversion surgery
- If tumour is found in the fistula diversion may not be considered