What is the optimal treatment plan for a middle-aged patient with internal soiling, a normal sigmoidoscopy, a mucosal bulge on the left side at the tip of the finger and indentation in the midline posterior on PR, and a pelvic MRI showing a mass on the left side at the level of the levator ani with no external opening?

Management of Perianal Fistula with Levator Ani Involvement

The optimal treatment for this middle-aged patient with an internal perianal fistula at the levator ani level with no external opening is the LIFT procedure (Ligation of Intersphincteric Fistula Tract). 1

Clinical Assessment and Diagnosis

The patient presents with:

• Internal cloth soiling
• Normal sigmoidoscopy
• PR examination showing mucosal bulge on left side at fingertip
• Posterior midline indentation
• MRI showing mass at the levator ani level
• No external opening

This presentation is consistent with a complex perianal fistula, likely transsphincteric, extending to the levator ani muscle. The absence of an external opening classifies this as a "blind" internal fistula.

Treatment Options Analysis

LIFT Procedure (Option D)

The LIFT procedure is the optimal choice for this patient because:

• It specifically addresses transsphincteric fistulas that extend to the levator ani 1
• It preserves sphincter function while providing high healing rates (60-90%) 2
• It's particularly indicated for complex fistulas with no external opening 1
• ECCO guidelines specifically recommend LIFT for complex perianal fistulas 1

Seton Placement (Option A)

While setons are useful in the management of perianal fistulas:

• They are primarily indicated as an initial step to control sepsis and create a patent tract 1
• They're typically used before definitive treatment rather than as a final solution 1
• For this patient without an external opening, seton placement would be technically challenging and less effective 1

Lay Open from Inside (Option B)

This approach:

• Is suitable primarily for simple, low fistulas (intersphincteric or low transsphincteric) 1
• Carries significant risk of sphincter damage and incontinence when used for complex fistulas at the levator ani level 2
• Is contraindicated for high transsphincteric fistulas due to the risk of incontinence 1

Sealing by Glue (Option C)

Fibrin glue:

• Has poor and variable healing rates (14-74%) 3
• Is less effective for complex fistulas at the levator ani level 2
• Shows high failure rates in long-term follow-up 3

Treatment Algorithm

1. Confirm diagnosis and classify fistula:

   • MRI is the gold standard for assessment of perianal fistulas 1
   • Examination under anesthesia to confirm internal opening location 1

2. Initial management:

   • Rule out and drain any associated abscess 1
   • Consider temporary seton placement if active inflammation is present 1

3. Definitive treatment with LIFT procedure:

   • Identify the intersphincteric portion of the fistula tract
   • Ligate and divide the tract at the intersphincteric space
   • Curette the remaining tract
   • Close the defect at the internal opening 2

4. Post-procedure management:

   • Monitor for healing and recurrence
   • Consider anti-TNF therapy if there's evidence of active Crohn's disease 1

Evidence Quality and Considerations

The ECCO guidelines (2024) provide the strongest evidence for this recommendation, stating that "In case of complex perianal fistulae, AF or LIFT can be offered, depending on fistula characteristics" 1. This is supported by multiple studies showing LIFT success rates of 60-90% for complex fistulas 2.

The absence of an external opening makes the LIFT procedure particularly suitable as it addresses the internal opening and intersphincteric portion of the tract, which are accessible in this patient 1.

Potential Complications and Pitfalls

• Recurrence: Even with LIFT, recurrence rates of 10-30% are reported 2
• Incomplete healing: May require additional procedures
• Missed secondary tracts: Thorough preoperative MRI and intraoperative assessment are essential
• Post-procedure pain: Generally less than with other techniques but still possible

The LIFT procedure offers the best balance of efficacy and sphincter preservation for this complex fistula case, making it the optimal choice among the presented options.