What are the treatment options for rectovaginal fistula?

Treatment of Rectovaginal Fistula

The treatment of rectovaginal fistula depends critically on etiology: malignant fistulas require immediate oncologic resection without any attempt at local repair, while inflammatory/Crohn's fistulas require medical optimization before surgical intervention, and simple obstetric/cryptoglandular fistulas can proceed directly to surgical repair after ruling out active inflammation. 1, 2

Critical First Step: Rule Out Malignancy

• Obtain contrast-enhanced pelvic MRI before any intervention to define anatomy and identify occult abscesses 2
• Never attempt local repair procedures (advancement flaps, sphincteroplasty) for malignant fistulas—these are contraindicated and will fail 1
• For confirmed malignant rectovaginal fistulas, oncologic resection with curative intent is the definitive treatment; fecal diversion provides palliation only when resection is impossible 1
• Medical therapy with anti-TNF agents has no role in malignant fistulas and delays definitive oncologic treatment 1

Treatment Algorithm for Non-Malignant Rectovaginal Fistulas

For Crohn's Disease-Related Fistulas

Initial Management (Mandatory First Steps):

• Perform examination under anesthesia (EUA) with surgical drainage of any sepsis—medical therapy without drainage is contraindicated when abscess is present 2
• Place loose, non-cutting setons after drainage to maintain fistula drainage and prevent abscess reformation 2
• Assess for active proctitis via proctosigmoidoscopy, as active rectal inflammation is an absolute contraindication to advancement flap 2
• Treat any active proximal luminal disease with appropriate medical therapy 3

Medical Therapy:

• Initiate combination therapy with infliximab (3-dose induction at weeks 0,2, and 6, then maintenance every 8 weeks) plus an immunosuppressive agent (azathioprine, 6-mercaptopurine, or methotrexate) 3, 2
• Concomitant immunosuppressive therapy is required to prevent human antichimeric antibodies that lead to infusion reactions and loss of efficacy 3
• Add antibiotics as adjuvant therapy initially 3
• Maintain setons for minimum 6-8 weeks while medical therapy takes effect—setons combined with optimal medical therapy can achieve closure in up to 98% of patients at median 33 weeks 2

Prerequisites Before Attempting Surgical Repair:

• Absence of active proctitis 2
• No rectal stricture 2
• Eradication of perianal sepsis 2
• Endoscopic healing of rectosigmoid mucosa 2
• Advancement flap is explicitly a second-stage procedure after initial seton drainage 2

Surgical Options for Crohn's Fistulas:

• Transanal advancement flap has 64% success rate (range 33-92%) in Crohn's patients, significantly lower than cryptoglandular fistulas 2
• Alternative approaches include transvaginal advancement flap and sleeve advancement flap, with success rates ranging from 50% to 100% 3
• Fistulotomy should rarely, if ever, be used for rectovaginal fistulas due to sphincter injury risk 3
• Continue concomitant immunosuppressive therapy when performing advancement flap 2

For Simple Obstetric/Cryptoglandular Fistulas

Conservative Management:

• Conservative treatment may be effective for minimal symptoms and small fistulas, attempted for 3-6 months 4
• This approach is appropriate only after ruling out inflammation and infection 4

Surgical Repair:

• Simple fistulas can proceed directly to local repair without prolonged medical optimization 4
• Cryptoglandular fistulas have 80% success rate with advancement flap (range 24-100%) 2
• Local repair options include primary closure, transanal advancement flap, transvaginal advancement flap, and sleeve advancement flap 3
• Modified Martius flap (bulbocavernosus fat flap interposition) offers 65-100% success rates for lower and middle rectovaginal fistulas 5

Special Considerations:

• If anal sphincter damage is present, repair sphincter muscles along with the fistula 4
• For high rectovaginal fistulas, consider transabdominal approach or robotic-assisted transanal repair 4, 6
• Interposition of healthy, well-vascularized tissue is required for complex or recurrent fistulas 4

Role of Fecal Diversion

• Construct diverting stoma initially for patients with severe symptoms and larger fistulas to provide symptom relief 4
• Temporary bowel diversion can be used as adjunct to primary repair, with reversal after 2 months once healing is confirmed 7
• For malignant fistulas where resection is not possible, fecal diversion provides palliation 1

Common Pitfalls to Avoid

• Never use cutting setons—they cause keyhole deformity and incontinence 2
• Do not attempt advancement flap with active proctitis present 2
• Do not discontinue immunosuppressives after achieving closure with infliximab—maintenance therapy is required 2
• Do not assume clinical closure equals complete healing—high recurrence risk exists without complete tract fibrosis 2
• Avoid local repair for malignant fistulas under any circumstances 1