Not all fistula-in-ano presentations carry the same surgical risk or complexity. When a patient presents with a simple fistula and intact sphincter function, a distinct evidence-based approach applies.
Simple anal fistulas lack the features that define complex fistulas. This scenario covers intersphincteric and low transsphincteric fistulas that involve less than 30% of the external anal sphincter, in patients with normal anal sphincter function. The extent of sphincter involvement is the central factor guiding management.
In this specific scenario, the evidence supports a surgical intervention targeting the fistula tract directly. The complete structured protocol — including procedural details, patient selection criteria, and perioperative considerations — is available in full via the link below.
Full protocol details available below ↓
DOI: 10.1097/DCR.0000000000002473
Simple anal fistulas have none of these complex features and, in general, include intersphincteric and low transsphincteric fistulas that involve less than 30% of the external sphincter.
Patients with a simple fistula-in-ano and normal anal sphincter function may be treated with lay-open fistulotomy.
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