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Anal fissure
Background
Overview
Definition
AFs refer to an anorectal disorder characterized by a tear in the squamous epithelium of the anus, distal to the dentate line. Fissures are defined as acute if present for < 6 weeks, and they are defined as chronic if present for > 6 weeks.
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Pathophysiology
Various risk factors increase the risk of AFs, mediating their effects via mechanical tissue trauma, ischemia of the anal canal, impaired sphincter structure or function, or anal hypertonicity.
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Epidemiology
The annual incidence of AFs in the US is estimated at 110 cases per 100,000 person-years.
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Disease course
AFs may cause clinical manifestations of anal pain, spasm, and/or bleeding with defecation.
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Prognosis and risk of recurrence
Medical treatment is associated with over 70% success rates. Surgical treatment, which is typically reserved for patients in whom medical therapy fails, yields excellent outcomes.
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Guidelines
Key sources
The following summarized guidelines for the evaluation and management of anal fissure are prepared by our editorial team based on guidelines from the American Society of Colon and Rectal Surgeons (ASCRS 2023,2017), the Italian Unitary Society of Colon-Proctology (SIUCP 2023), the American College of Gastroenterology (ACG 2021), the World Society of Emergency Surgery (WSES/AAST 2021), and the Association of Coloproctology ...
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Screening and diagnosis
Etiology: as per ACPGBI 2008 guidelines, recognize that AFs associated with internal anal sphincter hypertonia are probably ischemic in nature.
B
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Diagnosis
Differential diagnosis
Diagnostic investigations
Physical examination: as per SIUCP 2023 guidelines, consider performing clinical examination as the initial evaluation of sphincter hypertonia in patients with AF.
E
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Diagnostic imaging
Functional evaluation
Laboratory tests
Medical management
Indications for nonoperative management: as per ASCRS 2023 guidelines, offer nonoperative management as first-line therapy in patients with acute AF.
B
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Topical nitrates
Topical CCBs
Topical antibiotics and anti-inflammatory agents
Pain management
Nonpharmacologic interventions
Therapeutic procedures
Botulinum toxin injections
As per ASCRS 2023 guidelines:
Administer botulinum toxin injection as first-line therapy in patients with chronic AF and as second-line therapy following failed treatment with topical therapies.
B
Insufficient evidence to recommend repeat botulinum toxin injection in patients with recurrent AF, although short-term outcomes have shown good healing rates with a low risk of fecal incontinence.
I
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Anal dilatation
Tibial nerve stimulation
Surgical interventions
Indications for surgery
As per AAST/WSES 2021 guidelines:
Avoid performing surgery in patients with acute AF.
D
Consider performing surgery in patients with AF in the chronic phase not responding after 8 weeks of nonoperative management.
B
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Lateral internal sphincterotomy
Anocutaneous flap
Fissurotomy and fissurectomy