Untreated anal fistulas may lead to recurrent formation of a perianal abscess interspersed with partial healing of the fistula track (1).
Low fistulas can be efectively managed by fistulotomy while high fistulas requie more complex treatment e.g. - mucosal flap advancement, ligation intersphincteric fistula tract (LIFT) etc
Management of fstula can be described by the the acronym SNAP (sepsis, nutrition, anatomy, and procedure).
- sepsis - eradication of sepsis is the initial step
- nutrition - anal fistulas heal poorly in malnourished patients
- anatomy – it is important torecognise secondary tracks and failure to do so may lead to treatment failure
- procedure
- seton
- is a simple thread (usually a non-absorbable suture or vascular sling) running through the fistula tract creating a continuous ring between the internal and external openings
- is the first step in in treating a complex fistula
- it maintain patency of the fistula track, allow drainage, and prevent the development of perianal sepsis
- used primarly in high trans-sphincteric fistula, where division of greater than one third of the anal sphincter muscle risks incontinence
- a cutting seton (regular tightening of the seton to encourage gradual cutting through of the sphincteric muscle with associated inflammation followed by fibrosis) is another option for trans-sphincteric fistulas
- fistulotomy
- is the standard treatment for submucosal (low) fistulas because there is no risk to continence and recurrence is low (0-2%)
- operation involves division of superficial tissue and thus laying open of a fistula track, if there are any lateral extensions then these must also be laid open
- the patient will be in hospital for 3-10 days and will be off work for 2-4 weeks
- due to the risk of incontinence, use of this procedure for fistulas that involve the sphincter mechanism is controversial
- practic parameters have described that fistulotomy may be used in the treatment of simple perianal fistulas in cryptoglandular disease
- simple fistula was defined as a single non-recurrent track that crossed less than 50% of the external anal sphincter, but not the anterior sphincter in women, in people with perfect continence and no history of Crohn’s disease or pelvic radiation
- sphincter saving method
- fibrin glue – a combination of fibrinogen, thrombin, and calcium in a matrix is injected into the fistula track under general anaesthesia. not useful in complex fistulas and multiple tracks
- fistula plug - made from porcine small intestinal mucosa. It is pulled through the fistula track and secured in place at the internal opening, then trimmed at the external opening, which is left open for drainage
- endorectal advancement flap – the internal opening is covered with disease free anorectal wall
- ligation of the intersphincteric fistula track (LIFT) -
- a novel method of treating complex anal fistulas
- an incision is made between the internal and external anal sphincters and the intersphincteric tract is identified and ligated close to the internal opening. The fistula tract is curetted and the external sphincter opening is sutured (1)
- stem cell - is a novel treatment where adipose derived stem cells are cultured and injected into the fistula track, not available in most centres
- defunctioning proximal colostomy – for perianal sepsis difficult to control and with multiple tracks
For anal fistula in patients with Crohn’s disease
- infliximab (anti-tumour necrosis factor α antibody) is considered the first line treatment’
- surgery should be considered if medical therapy fails e.g. - d defunctioning colostomy is ucommonly used defunctioning colostomy
Tuberculosis should be suspected in patients who fail to respond to standard treatment or who develop recurrent fistulas. Antituberculous drugs are the first line treatment (1)
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