Urogenital fistulas (vesicovaginal fistula)

Definition

• Abnormal communication between the bladder and the vagina resulting in continuous leakage of urine through the vagina.
• Vesicovaginal fistula is the most common type of urinary tract fistula.

Aetiopathogenesis

Aetiology and pathogenesis

• In high-income countries vesicovaginal fistulas are mostly iatrogenic, usually resulting from an unrecognised bladder injury during gynaecological pelvic procedures.
• In low-resource countries the most common cause is prolonged obstructed labour, whose pressure necrosis destroys the tissue separating the bladder and vagina.
• Other causes include malignancy, radiogenic tissue damage, inflammation, infection, ischaemia, foreign bodies, trauma and congenital anomalies.

Clinical features

• The cardinal symptom is continuous leakage of urine from the vagina; recurrent urinary tract infections may also occur.
• Iatrogenic genitourinary fistulas typically occur as an early complication within the first 30 days.

Diagnosis

• The work-up comprises physical examination, dye testing, cystoscopy and CT urography.
• In the methylene blue test the dye is instilled retrogradely into the bladder; blue staining of a vaginal tampon indicates a vesicovaginal fistula.
• Staining of the tampon after oral phenazopyridine suggests a ureterovaginal fistula; the two tests combined form the double-dye test.
• Analysis of the vaginal fluid for urea, creatinine and potassium can suggest a genitourinary fistula.
• In 12–25% of vesicovaginal fistulas there is an associated ureterovaginal fistula.

Keep learning in the app

Further reading (selection)

1. StatPearls: Vesicovaginal Fistula (NCBI Bookshelf)
2. A comprehensive review of urinary tract fistulas (Ther Adv Urol 2025, PubMed Central)
3. Guided tour of hidden tracts in the pelvis: exploring pelvic fistulas (Arch Gynecol Obstet 2021, PubMed Central)

Cross-references