What are the differences in sensation changes between LIFT (Ligation of Intersphincteric Fistula Tract) surgery and fistulotomy in a patient with a low transsphincteric fistula and a history of receptive anal sex?

Sensation Changes: LIFT vs Fistulotomy in Low Transsphincteric Fistula

LIFT (Ligation of Intersphincteric Fistula Tract) preserves anal sensation and continence better than fistulotomy because it avoids dividing any sphincter muscle, making it the preferred option for patients with low transsphincteric fistula, particularly those with a history of receptive anal sex where sphincter preservation is critical. 1, 2

Key Differences in Sensation and Continence Outcomes

LIFT Procedure

• No sphincter division occurs, meaning anal sensation remains completely intact with no risk of sensory nerve damage 1, 3
• Zero incontinence reported in multiple studies, with no cases of gas or stool incontinence after LIFT 2
• Continence scores remain unchanged at 6 months post-operatively using validated Rockwood Fecal Incontinence Severity Index 1
• Success rate of 80-82% for primary healing in low transsphincteric fistulas 1, 2

Fistulotomy Procedure

• Divides the lower third of external anal sphincter, which inevitably damages sensory nerve fibers embedded in the sphincter complex 1
• Incontinence occurs in a measurable percentage of patients, with 2 out of 15 patients (13%) experiencing gas incontinence in comparative studies 2
• Higher risk in specific populations: female patients with anterior fistulas and those with pre-existing diminished sphincter function face "not insignificant" risk of impaired continence 1
• Success rate of 93-100% for healing, but at the cost of sphincter division 2, 4

Critical Considerations for Your Patient Population

For patients with history of receptive anal sex, sphincter preservation is paramount because:

• Baseline sphincter function may already be compromised from repetitive trauma 5
• Any additional sphincter division compounds existing weakness 5
• The American Society of Colon and Rectal Surgeons specifically warns that "unrecognized baseline sphincter compromise may be exacerbated by the procedure" 5

Contraindications That Must Be Ruled Out

Before either procedure, you must confirm:

• No active proctitis present on proctosigmoidoscopy, as this contraindications both procedures 6, 7
• No anterior fistula location in female patients, which has high incontinence risk with fistulotomy 7, 8
• Preserved baseline sphincter function documented by anorectal manometry 5

Recommended Approach

The 2024 ECCO Guidelines recommend LIFT as a treatment option for selected patients with complex perianal fistulae (EL3), while fistulotomy is recommended only for carefully selected patients with simple fistula in the absence of proctitis (EL4). 6

For your specific patient:

1. Choose LIFT over fistulotomy to preserve sensation and continence 1, 2
2. Accept the slightly lower healing rate (80% vs 93%) as a reasonable trade-off for complete sphincter preservation 2
3. If LIFT fails, the transsphincteric fistula converts to an intersphincteric fistula, which can then be treated with fistulotomy while still preserving the external sphincter 1

What This Means Practically

• Sensation preservation: LIFT maintains normal anal sensation because no sensory nerves are cut 1
• Faster healing: LIFT achieves complete wound healing in 4.5 weeks vs 5.7 weeks for fistulotomy 2
• Quality of life: Patients maintain normal sexual function and continence, which is critical for someone with history of receptive anal sex 1, 2

The European Society of Coloproctology states that "division of the lower part of the external anal sphincter is no longer necessary in the treatment of low transsphincteric fistulae, which is essential for patients with compromised anal sphincters." 1