Urogenital Fistula: Causes, Symptoms and Treatment

What Is a Urogenital Fistula?

A urogenital fistula is an abnormal, pathological channel (fistula) that forms between a part of the urinary tract and a part of the genital tract. These connections usually develop as a result of injury, surgery, or disease and cause urine to leak uncontrollably into the vagina, uterus, or other pelvic structures. Urogenital fistulas predominantly affect women. In low-income countries, they are most commonly caused by prolonged obstructed labor, while in high-income countries they more frequently occur as a complication of gynecological or urological surgery.

Causes

The causes of a urogenital fistula vary depending on geographic and clinical context:

• Obstetric complications: Prolonged obstructed labor results in sustained pressure from the fetal head on pelvic tissues, leading to reduced blood flow and tissue necrosis (tissue death).
• Surgical procedures: Gynecological operations such as hysterectomy (surgical removal of the uterus) or urological surgeries can inadvertently create fistulas.
• Radiation therapy: Radiotherapy in the pelvic area, such as for cervical or bladder cancer, can damage surrounding tissues and lead to fistula formation.
• Inflammatory conditions: Chronic inflammatory bowel diseases such as Crohn's disease can, in rare cases, cause urogenital fistulas.
• Malignant tumors: Pelvic cancers may invade adjacent structures and create fistulous tracts.
• Trauma: Injuries from accidents or sexual violence may also result in fistula formation.

Types of Urogenital Fistulas

Fistulas are classified according to the organs involved:

• Vesicovaginal fistula: A connection between the bladder and vagina -- the most common type.
• Ureterovaginal fistula: A connection between the ureter and vagina, often occurring after surgery.
• Uterovesical fistula: A connection between the uterus and bladder, frequently following cesarean section.
• Urethrovaginal fistula: A connection between the urethra and vagina.
• Vesicouterine fistula: A connection between the bladder and the cervix or uterus.

Symptoms

The hallmark symptom of a urogenital fistula is involuntary, continuous urine leakage (urinary incontinence), often experienced as constant wetness. Additional symptoms may include:

• Recurrent urinary tract infections
• Unpleasant odor due to persistent urine leakage
• Skin irritation and sores in the perineal area (dermatitis)
• Pelvic or lower abdominal pain, including pain during intercourse
• Psychological distress, social withdrawal, and depression

Diagnosis

Diagnosis of a urogenital fistula is based on a combination of clinical examination and imaging studies:

• Gynecological examination: Visual inspection of the vagina and cervix.
• Cystoscopy: Endoscopic examination of the bladder using a camera to directly visualize the fistula.
• Methylene blue test: Blue dye is instilled into the bladder; its appearance in the vagina confirms a vesicovaginal fistula.
• Imaging studies: CT urography, MRI, or intravenous urography to precisely locate and assess the fistula.
• Urography / renal scintigraphy: Used to evaluate ureteral involvement.

Treatment

Treatment of a urogenital fistula is in most cases surgical. The goal is complete closure of the fistula and restoration of normal urinary and genital tract function.

Conservative Management

In cases of very small or recently formed fistulas, spontaneous closure may be attempted through prolonged bladder catheterization. However, this approach is rarely successful on its own.

Surgical Repair

• Fistula excision and closure: The fistulous tract is surgically removed and the affected structures are closed in layers.
• Transvaginal approach: Often the preferred approach for vesicovaginal fistulas.
• Abdominal approach: Required for complex or difficult-to-access fistulas.
• Laparoscopic or robot-assisted surgery: Minimally invasive alternatives with good outcomes.

The optimal timing for surgery is debated, but repair is generally performed three to six months after fistula formation to allow adequate tissue healing. Prolonged catheterization is recommended postoperatively.

Supportive Measures

Psychosocial support, pelvic floor physiotherapy, and careful follow-up care are important components of comprehensive management.

Prognosis

With appropriate surgical treatment, the prognosis is favorable. Success rates for simple fistulas exceed 90%. Complex or recurrent fistulas may require multiple surgical procedures. Early diagnosis and treatment significantly improves the quality of life for affected individuals.

References

1. World Health Organization (WHO): Obstetric Fistula -- Guiding principles for clinical management and programme development. WHO Press, Geneva, 2006.
2. Zimmern P. et al.: Urogenital Fistulas -- Diagnosis and Management. In: Campbell-Walsh-Wein Urology, 12th edition, Elsevier, 2021.
3. Hilton P.: Urogenital fistula in the UK: a military trauma paradigm and its application to a civilian practice. BJU International, 2012; 110(11): 1724-1730.