Anal Fistula Surgery

There are many types of operations to choose from for anal fistulae.

The main problems with all these operations are that none of them are able to provide a 100% guarantee of success and healing of the fistula, with no risk to normal continence and function of the anus. We will explain this to you in detail at the time of your consultation.

At Brisbane Colorectal we will often recommend a combination of procedures, giving the patient a maximal chance of healing of the fistula. This may require a longer operation, or a longer hospital stay, but with a better chance of successful healing of the fistula. Different anal fistulae are best served with different operations, and we tailor the surgery we recommend to each patient’s fistula depending on a number of factors.

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Types of anal fistula surgeries

Some of the operations more commonly used are listed below (this is not an exhaustive list). All of these surgeries are performed under general or spinal anaesthetic:

Fistulotomy (“Laying open of the fistula”)

How it works

A fistulotomy is performed for anal fistulae which are near the surface of the body.

About the procedure

The operation is done as a day procedure. An incision is made through the skin over the tunnel of the fistula, and in doing so the fistula is turned into an external wound, which will then heal from the base up.

This operation is only performed if there is plenty of anal sphincter muscle left above the surgical wound, and the risk of any future minor leakage is very small. It has a very high success rate of approximately 95% for complete healing.


Healing usually takes about 3 weeks to occur on average, and a small scar is left instead of the fistula. This scar usually fades over several weeks/months.

LIFT procedure (“Ligation of the Intersphincteric Fistula Tract”).

This operation is used for anal fistulae which are deeper inside the anus. This surgery carries a minimal risk to anorectal function, and a success rate of 50-60%.

How it works

A small incision is made in between the internal and external anal sphincter muscles, and the fistula tract is identified, sutured closed on each side and divided.

Mucosal/anodermal advancement flap

In this operation, closure of the internal opening of the fistula, inside the anal canal, is performed. Success rates are about 50-60%. Small dissolvable sutures are used and eventually the area scars up after healing.

How it works

A small flap of tissue is created, and this is used to ensure a complete closure of the internal opening, ultimately leading to healing.

Video-assisted anal fistula tract surgery (VAAFT)

Video-assisted anal fistula tract surgery is used as an “adjunct” to some fistula operations at Brisbane Colorectal.

VAAFT may increase the success of fistula repair surgery, particularly for more longstanding fistulae, and we offer this at Brisbane Colorectal as a novel technique.

How it works

A small endoscope is passed into the anal fistula itself, and fistula tract is irrigated with fluid to remove any debris. The inner lining of the fistula tract is then cauterized to create a fresher wound and definitive repair is then performed.

Core fistulectomy

Anal fistula surgery aims to offer the best chance of complete healing for the patient. Removal of some, or all, of the fistula tract itself can sometimes lead to this if it can be done without injury or damage to the remaining anal tissue. At Brisbane Colorectal, we usually aim to remove as much of the anal fistula tract as possible, as much as can be safely done without damage to the anal sphincter. This leads to an increased chance of cure.

Negative pressure drainage of the fistula wound

A new technique for anal fistula surgery used at Brisbane Colorectal involves “negative pressure therapy”.

How it works

At the time of fistula surgery, a tiny tube is placed into the surgical wound, secured to the skin and connected to a low pressure suction device. This allows any residual fluid from the anal fistula or the surgery itself to be gently sucked out of the wound. This fluid, if left undrained, may accumulate and burst through the fistula repair leading to failure.

About the procedure

In selected cases we have found our success rates for anal fistula surgery have improved by using this technique.

Anal fistula plug

An anal fistula plug is sometimes used for complex anal fistulae and fistulae between the anus/rectum and the vagina. An anal fistula plug is a specially designed, completely absorbable, material made in the shape of an anal fistula.

How it works

At the operation, the anal fistula plug is gently placed into the anal fistula and used to completely fill the fistula tunnel. The internal opening is then closed, and the body grows scar tissue into the mould of the anal fistula plug as it slowly dissolves.

About the procedure

The advantage of the procedure is that the risk is very low. Success rates are about 30-40%.

Draining Seton

Some people prefer to live with a small Seton across their anal fistula. This may be suitable for patients with very complex fistulae, previous failed surgery, or for patients with Crohn’s disease-related anal fistulae. Whilst the fistula remains, some people find this a suitable management strategy, avoiding further surgery.

How it works

This involves a short operation under general anaesthetic, with the placement of a small plastic tube or silk thread (called a “Seton”) through the tunnel of the fistula.

About the procedure

Usually, the Seton is visible on the outside of the anus, but tends to be tolerated very well by patients. It can sometimes interfere with cleaning of the anus after going to the toilet and occasionally patients prefer to have a shower after using their bowels when they have a Seton in place. The Seton keeps the skin openings of the fistula open and encourages drainage of the fluid, preventing any infection.

A Seton is frequently used as a temporary measure to control a fistula, prior to definitive surgery; but in some cases if the Seton is tolerated very well by the patient it is also an option for longer-term management.

Cutting Seton

A cutting Seton is another option for people with complicated anal fistulae. Whilst not used much these days, a cutting Seton remains a reasonable option for patients with fistulae which are difficult to heal.

How it works

In this procedure, a silk thread is passed around the fistula and tied together snugly. The procedure is mildly/moderately uncomfortable afterwards for a few days, and the cutting Seton works by gradually pulling the fistula closer to the skin. The body replaces the tissue behind it with scar tissue.


The downside is that the procedure needs to be repeated several times (usually between 3-7 times) and it takes months for the fistula to finally reach the skin and heal completely. There is a small risk of disturbed anal function and hence this procedure is only used selectively for complex fistulae.

What follow-up is required after anal fistula surgery?

Unfortunately, there is no guarantee of success with anal fistula surgery, regardless of what operation has been performed. At Brisbane Colorectal we will continue to see our anal fistula patients until healing has been achieved, and we are always available should any further problems arise in the future.

For patients who have had an anal fistulotomy (“laying open of the fistula”), we usually see patients 6 weeks after surgery to ensure the wound is completely healed. If it has not, we will make a plan to facilitate healing and occasionally our wound therapists become involved in patient care if needed.

Following any definitive fistula operation, there is a risk of a fistula coming back, out to 6-12 months following the surgery. 80% of fistula “recurrences” occur within 6 months of the surgery, and this can manifest as another abscess, the skin re-opening, or another fistula forming.

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