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?

Optimal Treatment for Complex Perianal Fistula with Levator Ani Involvement

The LIFT (Ligation of Intersphincteric Fistula Tract) procedure is the optimal treatment for this patient with a complex perianal fistula extending to the levator ani muscle without an external opening. 1

Clinical Assessment and Diagnosis

The clinical presentation strongly suggests a complex transsphincteric perianal fistula:

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

This represents a complex fistula with high transsphincteric extension to the levator ani muscle, requiring a sphincter-preserving approach.

Treatment Rationale

Why LIFT is the Best Option:

1. Specifically designed for transsphincteric fistulas that extend to the levator ani level 1
2. High healing rates of 60-90% for complex fistulas 1, 2
3. Preserves sphincter function with lower risk of incontinence compared to other techniques 1
4. Recommended by ECCO guidelines specifically for complex perianal fistulas with these characteristics 1

Why Other Options Are Inferior:

• Seton placement (Option A): While useful as an initial step to control sepsis and create a patent tract, setons are primarily indicated as a temporary measure before definitive treatment rather than a final solution 1. They would not provide definitive closure of this complex fistula.

• Lay open from inside (Option B): This approach carries a high risk of sphincter damage and subsequent incontinence in complex fistulas extending to the levator ani, making it inappropriate for this case 2, 3.

• Sealing by glue (Option C): Fibrin glue shows poor and highly variable healing rates (14-74%) 3, making it unreliable for this complex fistula.

Procedural Considerations

For optimal outcomes with the LIFT procedure:

• Thorough preoperative MRI assessment is essential to identify any secondary tracts
• Careful intraoperative identification of the internal opening is critical
• The procedure should specifically target the intersphincteric portion of the fistula tract

Post-Procedure Management

• Monitor for healing and recurrence
• Consider anti-TNF therapy if there's evidence of underlying Crohn's disease 1
• Follow-up imaging may be necessary to confirm complete resolution

Important Caveats

• Success rates for LIFT vary between studies (60-90%), and patients should be informed about potential recurrence 2
• The absence of an external opening makes this case particularly suited for LIFT, as other techniques like fistulotomy would be technically challenging and risk greater sphincter damage
• If LIFT fails, newer techniques like video-assisted anal fistula treatment (VAAFT) could be considered as a secondary option, though they are more expensive and less established 3, 4, 5