Table 1 Categorisation, causes and mechanisms of entero-vaginal fistulas
Type | Cause | Notes |
|---|---|---|
Colovaginal | Complicated colonic diverticulitis | Patients with prior hysterectomy Either (a) inflamed sigmoid colon directly adheres to the vaginal vault or (b) via formation of interposed abscess that opens in the vagina |
Rectovaginal | Past irradiation such as for uterine cervix carcinoma | Delayed onset (years after treatment) Increasingly uncommon |
Primary or recurrent pelvic tumours | Either (a) rectal carcinoma invading the vagina or (b) gynaecologic malignancies invading the rectum | |
Surgical injury | ||
- Low anterior resection for rectal cancer | Risk up to 5–10% of patients, part of anastomotic leakage spectrum Inadvertent clipping of vagina in staples | |
- Pelvic floor surgery | With positioning of prosthetic mesh | |
- Haemorrhoid surgery | ||
Anovaginal | Crohn’s disease (CD) | CD = 25% of all vaginal fistulas (VF) VF < 4–9% of all CD-related perianal inflammatory disease Often complex forms |
Ulcerative colitis | Perianal inflammatory disease (rare) Ileal pouch-anal anastomosis leakage | |
Cryptoglandular or other inflammation | E.g. Bartholin’s gland abscess | |
Perineal laceration | From either (a) direct trauma (often sexual violence) or (b) obstetric injury (spontaneous or instrumental delivery) |