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 per rectal (PR) examination, and a pelvic MRI showing a mass on the left side at the level of the levator ani with no external opening?

Optimal Treatment for Complex Perianal Fistula with Levator Ani Involvement

The LIFT (Ligation of Intersphincteric Fistula Tract) procedure is the optimal treatment choice for this patient with a complex perianal fistula extending to the levator ani muscle with no external opening. 1

Clinical Assessment and Diagnosis

Based on the clinical presentation:

• Internal cloth soiling
• Normal sigmoidoscopy
• PR examination showing mucosal bulge on the left side at the tip of the finger
• Indentation in the midline posterior
• MRI showing mass on the left side 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.

Treatment Options Analysis

Option A: Seton

• Setons are primarily indicated as an initial step to control sepsis and create a patent tract
• They are typically used before definitive treatment rather than as a final solution 1
• While useful for drainage and inflammation control, setons alone are not optimal for definitive management of complex fistulas with no external opening 2

Option B: Lay open from inside

• Fistulotomy (laying open) is contraindicated for complex fistulas involving a significant portion of the sphincter
• This approach carries high risk of incontinence when used for fistulas at the level of the levator ani 3
• Not recommended for complex fistulas with high sphincter involvement 4

Option C: Sealing by glue

• Fibrin glue shows poor and variable healing rates (14%-74%) 4
• Less effective for complex fistulas, particularly those extending to the levator ani
• High failure rates make this suboptimal for definitive treatment 4

Option D: LIFT (Ligation of Intersphincteric Fistula Tract)

• Specifically addresses transsphincteric fistulas that extend to the levator ani
• High healing rates of 60-90% for complex fistulas 1, 3
• Preserves sphincter function with lower risk of incontinence 1
• Recommended by guidelines for complex perianal fistulas 1

Rationale for LIFT Procedure

1. Sphincter preservation: The LIFT procedure preserves sphincter function, which is crucial for maintaining continence in complex fistulas 3

2. Efficacy for complex fistulas: LIFT has demonstrated high healing rates (60-90%) specifically for complex fistulas like the one described 1, 3

3. Anatomical suitability: The procedure is particularly suited for transsphincteric fistulas extending to the levator ani, matching this patient's presentation 1

4. No external opening: LIFT can address fistulas without external openings, as in this case 1

Procedural Considerations

• Thorough preoperative MRI assessment is essential to identify any secondary tracts
• Intraoperative examination to confirm the internal opening location
• The procedure involves identifying the intersphincteric portion of the fistula, ligating and dividing the tract

Potential Pitfalls and Caveats

• Success rates may be lower if there is active inflammation or abscess formation
• Careful identification of the internal opening is crucial for success
• Recurrence is possible (10-40% of cases) and may require additional procedures
• Alternative sphincter-preserving techniques like advancement flaps could be considered if LIFT fails

Follow-up Management

• Regular monitoring for healing and recurrence
• Assessment for any signs of incontinence
• Consideration of additional imaging if symptoms persist or recur