What are the treatment options for rectovaginal fistula?

Treatment for Rectovaginal Fistula

For Crohn's-related rectovaginal fistulas, initiate infliximab combined with an immunomodulator as first-line therapy, and only proceed to surgical repair after achieving complete endoscopic healing of the rectosigmoid mucosa. 1

Medical Management: The Foundation of Treatment

Initial Medical Therapy

• Start anti-TNF therapy (infliximab) immediately as the cornerstone of treatment, which achieves prolonged fistula closure in 45% of rectovaginal fistulas, with maintenance therapy extending median closure duration to 46 weeks versus 33 weeks with placebo 1

• Always combine infliximab with an immunomodulator (azathioprine, 6-mercaptopurine, or methotrexate) from the outset to prevent immunogenicity and maintain remission 2, 1

• Use the standard induction regimen: infliximab at weeks 0,2, and 6, followed by maintenance dosing every 8 weeks 1

• Consider temporary adjunctive antibiotic therapy during the initial treatment phase 2

Critical Pre-Surgical Requirements

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

• Control any active luminal inflammatory disease in the rectosigmoid colon with conventional corticosteroids, azathioprine, 6-mercaptopurine, methotrexate, or infliximab before considering surgery 2

• Ensure no anorectal stricture is present before surgical intervention 2, 1

Surgical Management: When and How

Patient Selection for Surgery

• Only attempt surgery in patients with disabling symptoms after medical optimization, as there is significant risk of worsening symptoms if the operation fails 1

• Asymptomatic low anal-introital fistulas may not require surgical treatment at all 1

Surgical Options (in Order of Preference)

For Simple, Low Fistulas:

• Advancement flaps (transanal or transvaginal) are the preferred surgical approach for symptomatic fistulas with healed rectal mucosa, achieving a healing rate of 44.2% when combined with medical treatment 1

• Primary closure with sphincter repair achieves success in 53.1% of cases and should be considered for low-lying, simple fistulas 3

• Success rates for primary closure and advancement flaps range from 50% to 100% 2

For Complex Fistulas:

• Gracilis muscle interposition achieves 50% healing rate at 21 months median follow-up and is reserved for complex cases after advancement flap failure 1

• Seton placement is recommended for complex fistulas or those with active inflammation, allowing drainage while medical therapy takes effect 1

• Abdominal resections with or without proximal diversion achieve 55.2% success rates in selected patients 3

What NOT to Do Surgically

• Never use fistulotomy for rectovaginal fistulas due to high sphincter injury risk 2

• Do not use anal fistula plugs routinely - they are no more effective than seton removal alone and trend toward more adverse events 1

• Fibrin glue and fistula plugs have among the lowest success rates (18.2%) and should be avoided 3

Management of Refractory Disease

Fecal Diversion

• For treatment-refractory cases, fecal diversion with defunctioning ileostomy or colostomy provides early clinical response in 63.8% of patients 1

• Be aware that stomas often become permanent, with only 16.6% achieving successful reversal 1

• The rate of proctectomy after failed temporary diversion is 41.6% 1

Last Resort Options

• Proctectomy is reserved for refractory complex perianal disease despite defunctioning stoma, though it carries substantial risk of non-healing perineal wounds and long-term recurrence 2, 1

• Historically, proctectomy rates for patients with perianal Crohn's disease managed conservatively range from 10% to 18% 2

Critical Pitfalls to Avoid

• Never attempt surgical repair with active rectal inflammation - this guarantees failure 1

• Never delay oncologic treatment if malignancy is suspected - medical therapy with anti-TNF agents has no role in malignant fistulas 4

• Never attempt local repair procedures (advancement flaps, sphincteroplasty) for malignant fistulas - these are contraindicated and will fail; oncologic resection is required 4

• Do not offer advancement flap surgery to patients with mild symptoms, as failure can worsen their condition 1

• Do not assume clinical closure equals complete healing - high risk of recurrence exists without complete fibrosis of the tract 1

Special Considerations

Non-Crohn's Etiologies

• Conservative treatment may be effective in rectovaginal fistulas with minimal symptoms and should be attempted for small fistulas for a 3-6 month period 5

• The highest surgical success rate is observed among patients whose fistula etiology is malignancy (68.8%), followed by unknown causes (57%) and iatrogenic causes (43.8%) 3

Long-Term Monitoring

• Monitor chronic fistula tracts for malignancy development, particularly in long-standing cases, as squamous cell carcinoma, basal cell carcinoma, and adenocarcinoma can develop 2, 1

• Be aware that even with "successful" closure, patients may experience new complications including dyspareunia (36%), urination problems (21%), and new pain patterns 6