Genitourinary fistula
A genitourinary fistula is an abnormal "tunnel" or hole that forms between the urinary tract (the bladder, ureter or urethra) and another organ, most commonly the vagina. Because urine can travel down this abnormal opening, it leaks out continuously through the vagina, even when you are not trying to pass urine.
The most common types are:
• Vesicovaginal fistula (VVF): a hole between the bladder and the vagina. This is by far the most common type.
• Ureterovaginal fistula: a hole between the ureter (the tube that carries urine from the kidney to the bladder) and the vagina.
• Urethrovaginal fistula: a hole between the urethra (the tube you pee through) and the vagina.
• Vesicouterine fistula: a hole between the bladder and the uterus — uncommon, but classically seen after caesarean delivery
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What causes a genitourinary fistula?
A fistula is the body’s way of healing where it shouldn’t. Anything that injures the wall between the urinary tract and the vagina can lead to one. In Australia, the most common causes are:
• Pelvic surgery — by far the leading cause. Hysterectomy (removal of the uterus) for benign or cancer-related reasons is the single most common precursor.
• Childbirth injuries — including prolonged or obstructed labour, instrumental delivery, or missed bladder injury during caeserean section.
• Pelvic radiotherapy — for cervical, uterine, bladder or bowel cancers. Radiation injury can appear months to years after treatment.
• Pelvic cancers — a tumour can erode through the wall between organs.
• Inflammatory conditions — such as Crohn’s disease, diverticulitis, endometriosis or severe pelvic infection.
• Foreign bodies or trauma — retained pessaries, road or sporting trauma, or penetrating injuries.
Globally, obstructed childbirth without timely caesarean access remains the leading cause, but this is uncommon in Australia.
What are the symptoms of genitourinary fistula?
The hallmark symptom is continuous, painless leakage of urine from the vagina. You may notice:
• Wet underwear or pads despite emptying your bladder normally
• A constant trickle that does not stop when you sit, stand or sleep
• Recurrent urinary tract infections (UTIs)
• Skin irritation, rash or odour around the vulva and inner thighs
• Sometimes, passing urine that smells unusual, or seeing fluid from the vagina after passing urine
In a ureterovaginal fistula, you may still pass normal urine through the urethra and have leakage from the vagina at the same time. This is because one ureter is going to the bladder normally and the other is leaking into the vagina.
Symptoms typically appear 1–3 weeks after pelvic surgery, but a fistula caused by radiation can appear months or years later.
How is a genitourinary fistula diagnosed?
Diagnosis usually involves three steps: a careful history, an examination, and a small number of targeted tests.
Your specialist will ask about previous surgery, childbirth, cancer treatment and the exact pattern of leakage — when it started, whether it is constant or intermittent, and whether you still pass urine normally.
Clinical examination
A speculum examination of the vagina is performed gently in the clinic which usually revealed constant pool or trickle of urine in the vagina. A small or healed fistula can sometimes be hard to see, which is why dye tests are useful.
Dye and water tests
• Methylene blue (dye) test: blue dye is placed into the bladder. If blue fluid appears in the vagina, it confirms a vesicovaginal fistula.
• Three-swab test: three cotton swabs are placed in the vagina, dye is instilled into the bladder, and the swabs are inspected to help locate the leak.
Investigations are chosen to confirm the diagnosis, find the exact location of the fistula, look for more than one fistula, and rule out cancer or another underlying problem.
• Cystoscopy: a small camera is passed into the bladder to see the fistula opening directly and to check ureter openings.
• CT urogram or MRI of the pelvis: detailed imaging to map the urinary tract and surrounding tissue, particularly useful for ureteric or complex fistulas.
• Intravenous urogram (IVU): an X-ray study after contrast dye is given, used to assess kidney and ureter anatomy.
• Cystogram or VCUG: contrast is placed into the bladder and X-rays are taken to look for contrast dye leakage.
• Urodynamics: sometimes used if there is associated bladder dysfunction.
What investigations might I need?
How is a genitourinary fistula treated?
A small number of very small, early fistulas can heal by themselves if the bladder is kept empty with a catheter for 4–6 weeks. Most, however, require surgical repair. The right operation depends on the type and location of the fistula, the cause, and the quality of the surrounding tissue.
Conservative (non-surgical) management
• Continuous bladder drainage with a urethral catheter for several weeks
• Antibiotics for infection prevention
• Topical oestrogen cream to improve tissue quality before surgery
• Skin barrier creams to protect the vulva and thighs from constant moisture
Fistula surgery
Surgery is the definitive treatment. Approaches include:
• Transvaginal repair: the repair is performed through the vagina — usually preferred for low, simple fistulas such as vesicovaginal fistula.
• Transabdominal (open or laparoscopic/robotic) repair: used for high, complex, ureteric or recurrent fistulas.
• Ureteric reimplantation: the ureter is re-joined to the bladder when the fistula involves the ureter.
• Tissue interposition flaps: healthy tissue (for example, a Martius fat-pad flap or omentum) is placed between the bladder and vagina to reinforce the repair, especially after radiation or large fistula defect.
Success rates for a first repair in carefully selected, non-radiated fistulas are typically 85–95%.
What is the recovery like after fistula repair?
• Most patients stay in hospital for 1–2 nights depending on the approach.
• A urinary catheter is usually kept in for 10–21 days to keep the bladder empty while the repair heals.
• You will be advised to avoid heavy lifting, intercourse and tampons for around 6–12 weeks.
• A follow-up cystogram is often done before the catheter is removed to confirm watertight repair .
Can a genitourinary fistula come back?
Yes. Recurrence is uncommon after a well-planned first repair, but possible, especially in radiated tissue or when there is underlying cancer. Repeat repair is still successful in most cases when performed by an experienced surgeon, sometimes with additional tissue flaps.
Disclaimer: This information is intended as a brief guide to genitourinary fistula management. Dr Yong will be able to provide a more specific assessment and advice before making any decision on further treatment.