What are the management options for a rectovaginal fistula?

Management of Rectovaginal Fistula

Initial Approach: Multidisciplinary Medical Control Before Surgery

Rectovaginal fistulas in Crohn's disease require combined medical and surgical management, with medical therapy to control inflammation preceding any surgical intervention. 1

Medical Therapy as First-Line Treatment

• Anti-TNF therapy (infliximab) is the cornerstone of medical management, achieving prolonged fistula closure in 45% of rectovaginal fistulas, with maintenance therapy extending median closure duration to 46 weeks versus 33 weeks with placebo 1

• Combine anti-TNF agents with immunomodulators (azathioprine, 6-mercaptopurine, or methotrexate) both to prevent immunogenicity and maintain remission 1

• Surgical repair can ONLY proceed after achieving endoscopic healing of the rectosigmoid mucosa - this is a critical prerequisite that cannot be bypassed 1, 2

• Control active luminal inflammatory disease in the rectosigmoid colon with standard medical therapy (corticosteroids, immunomodulators, or biologics) before considering surgery 1

Imaging and Assessment

• MRI is the preferred imaging modality to define fistula anatomy and assess surrounding inflammation 2

• Endoanal ultrasound serves as an alternative or complementary technique with 90-100% positive predictive value 2

• Clinical closure does not equal radiographic closure - high recurrence risk exists without complete fibrotic tract on MRI 2

Surgical Management Algorithm

When Medical Therapy Fails or Fistula Persists

Surgery should only be attempted in patients with disabling symptoms after medical optimization, as there is significant risk of worsening symptoms if the operation fails. 1

Surgical Options (in order of consideration):

1. Advancement Flaps (transanal or transvaginal):

   • Reserved for symptomatic fistulas with healed rectal mucosa and no anorectal stricture or active rectal disease 1, 2
   • Combined medical and surgical treatment achieves healing in 44.2% of cases 1

2. Gracilis Muscle Interposition:

   • Achieves 50% healing rate in Crohn's-associated rectovaginal fistulas at 21 months median follow-up (compared to 60-90% in non-Crohn's fistulas) 1
   • Consider for complex cases after advancement flap failure 2

3. Seton Placement:

   • Recommended for complex fistulas or those with active inflammation 2
   • Allows drainage while medical therapy takes effect 1

Refractory Disease Management

For treatment-refractory cases, fecal diversion with defunctioning ileostomy or colostomy provides early clinical response in 63.8% of patients, though stomas often become permanent with only 16.6% achieving successful reversal. 1

• Fecal diversion improves symptoms and quality of life significantly 1
• The rate of proctectomy after failed temporary diversion is 41.6% 1
• Proctitis increases risk of permanent diversion 1

Proctectomy is the last resort for refractory complex perianal disease despite defunctioning stoma, though it carries substantial risk of non-healing perineal wounds and long-term recurrence 1

Critical Pitfalls to Avoid

• Never attempt surgical repair with active rectal inflammation - this guarantees failure 1
• Do not use anal fistula plugs routinely - they are no more effective than seton removal alone (33.3% vs 15.4% closure) and trend toward more adverse events 1
• Advancement flap surgery should not be offered to patients with mild symptoms, as failure can worsen their condition 1
• Recognize that some women may rationally choose to accept residual fistula drainage over proctectomy with permanent ostomy to optimize quality of life 1

Special Considerations

• Asymptomatic low anal-introital fistulas may not require surgical treatment 2
• Radiation therapy and prior pelvic surgery are the most important poor prognostic factors for successful closure 3
• Crohn's disease shows a tendency toward poor prognosis compared to other etiologies 3
• Monitor chronic fistula tracts for malignancy development, particularly in long-standing cases 2