Navigating peri-anal fistulas: A guide

In his latest online article, Mr Vijitha Chandima Halahakoon gives us his insights into peri-anal fistula. He talks about what it is, causes, risk factors, typical symptoms and signs, available treatment, what video assisted anal fistula treatment is and what a seton thread is.

What is a peri-anal fistula?

Peri-anal fistula is an abnormal connection between the anus or rectum with the skin around the anus.

What are the causes and risk factors associated with peri-anal fistulas?

Out of the many theories about the causation of peri-anal fistulas, the most common cause is a blockage of one of the anal glands that then lead to infection. A skin infection of the perineum (skin around the anus) is the second most common cause. However, there are other rare causes like, Crohn’s disease, tuberculosis, and very rarely anal cancer, etc.

What are the typical symptoms and signs of a peri-anal fistula?

The typical symptoms are a discharge (pussy, bloody or feculent) through an abnormal opening away from the anus close to the anal orifice. However, peri-anal fistulas can present as recurrent peri-anal abscesses or sepsis as well.

How is a peri-anal fistula diagnosed by healthcare professionals?

It is a clinical diagnosis of demonstrating an abnormal opening around the anus with a discharge in a patient with typical symptoms. An imaging modality, like MRI scan, can be of help to delineate the anatomy of the fistula.

What are the available treatment options for peri-anal fistulas, and how effective are they?

Historically there have been many surgical options to achieve a cure for peri-anal fistulas.

Out of all these, lay opening of the fistula gives the best chance of cure. However, the fistula needs to be below the anal muscles for this to be offered – to avoid chance of incontinence.

Other options are Video Assisted Anal Fistula Treatment (VAAFT), Ligation of the Inter-sphincteric Tract (LIFT), Fistula plugs, Fistula glue, etc.

If none of the above is feasible, then a Seton thread can be placed as a temporising measure until the sepsis settles and the tracts mature, so that a definitive procedure can be offered later.

What is Video Assisted Anal Fistula Treatment (VAAFT)?

Minimally invasive procedures like Video Assisted Anal Fistula Treatment (VAAFT) have the advantage of early recovery, minimal pain, and an early return to work. VAAFT does not involve tissue excision, and as such, there will be no more scars than what the patient already has. VAAFT can also be done as a day-case procedure under general anaesthesia, and carries a healing rate of around 70 per cent. The procedure can be repeated if it fails. The biggest advantage of a VAAFT is, as it does not involve any new wounds of tissure excision, the chance of injury to anal muscles and subsequent incontinence are very rare.

What is a Seton thread?

This is a temporising measure when other options are not feasible for any reason. A fine thread (commonly a thick suture thread) is threaded along the fistula tract and tied outside the anus. Seton threads can be used as drainage or cutting. Drainage Setons are the most used. They are kept loose for the fistula to drain and the sepsis to settle. Once the sepsis settles and the fistula tract matures, a more definitive option can be considered, usually after about three months. On the other hand, cutting Setons are rarely sued these days and intends to cut through the muscles and lay open the fistula gradually while allowing the muscles to heal with fibrosis – reducing the risk of incontinence.

Mr Vijitha Chandima Halahakoon is an esteemed consultant general surgeon with over 20 years of experience. You can schedule an appointment with Mr Halahakoon on his Top Doctors profile.