Hills Colorectal Surgery deals with anorectal problems such as haemorrhoids, anal fissure, anal fistula, pilonidal sinus, perianal abscess, pruritus ani and rectal prolapse. These are some of the many conditions that occur around the anus that cause significant discomfort and irritation. They may be associated with an itch, discharge, bleeding, pain or lump. The first step to deal with these problems is a thorough assessment and accurate diagnosis. Once the diagnosis is established, there is a range of treatments available, ranging from dietary manipulation, topical ointments to surgical procedures, which aim to improve or eradicate these problems.
Anal fistula is an abnormal communication between the innermost lining of the anal canal and the perianal skin.
Anal fistulae are formed as a result of infection of the anal glands which are located between the two layers of the anal sphincters. The glands usually secrete mucus to lubricate the stool. When the outlet of these glands becomes blocked, an abscess can form which can eventually point to the skin surface. The communication between the opening on the skin where the pus drains and the internal opening where the blockage occurred previously forms the anal fistula track.
After drainage of perianal abscess, about 50% of the wound heals without any further problem. The other 50% of patients will either experience recurrence of abscess or persistent discharge from the wound. This is usually related to an underlying anal fistula.
The persistent discharge from anal fistula can give rise to persistent “wetness” in the perianal area, discomfort and itchiness. In addition, recurrent abscesses may lead to significant pain and provides a source for systemic spread of infection.
Surgery is considered essential in the treatment of anal fistula. A perianal abscess should be drained in a timely fashion. Repair of the fistula is an elective procedure. The type of procedure performed depends on the anatomy of the anal fistula track.
For a simple fistula, i.e. the fistula track only incorporates superficial lower part of anal sphincters, an anal fistulotomy can be performed. This involves defining the track with a probe and then divides the anal muscles down onto the probe. In most instances, the risk of faecal incontinence is low as only the superficial muscle fibres were divided.
For a complex fistula, i.e. one that incorporates significant amount of anal sphincters involving the upper half of anal muscles, a seton is usually inserted as a temporary measure to control the sepsis. A definitive operation will then be contemplated at a later stage.
There are many operations described for the definitive treatment of a complex fistula. Dr Chew’s current preferences are anal sphincter advancement flap and the use of Glubran 2. Anal sphincter advancement flap is an operation that Dr Chew designed in 2005 and the initial results were published in an American journal titled Diseases of the Colon and Rectum in 2007. Click here to view the article.