Treatment of Complex Anal Fistula: Transsphincteric, Suprasphincteric, Extrasphincteric, and Horseshoe Fistulas
Clinical Scenario
This protocol addresses the management of complex anal fistula — a category that carries higher risk of sphincter injury and functional compromise than simple low fistulas.
Defining Features of This Presentation
Complex anal fistulas include transsphincteric fistulas that involve greater than 30% of the external sphincter, as well as suprasphincteric, extrasphincteric, and horseshoe fistulas. The category also covers anal fistulas associated with preexisting fecal incontinence or chronic diarrhea — each of which raises the functional stakes of any surgical approach.
Approach
Management in this setting centres on staged, sphincter-sparing procedures designed to achieve fistula closure while protecting continence. Several definitive surgical options are available depending on fistula anatomy and patient factors.
The complete selection criteria, procedural sequence, and technique-specific indications are in the full protocol below.
References
- Complex anal fistulas include transsphincteric fistulas that involve greater than 30% of the external sphincter, suprasphincteric, extrasphincteric, or horseshoe fistulas and anal fistulas associated with IBD, radiation, malignancy, preexisting fecal incontinence, or chronic diarrhea.
- Fistula-in-ano may be treated with endorectal advancement flap.
- Transsphincteric fistulas may be treated with ligation of the intersphincteric fistula tract (LIFT) procedure.
- A cutting seton may be used selectively in the management of complex cryptoglandular anal fistulas.
DOI: 10.1097/DCR.0000000000002473
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