Anal fistula treatment

An anal fistula is an abnormal tunnel that develops between the anal canal or rectum and the skin around the anus. Most anal fistulas arise as a result of an anal abscess, which is a localized collection of pus caused by infection in the tissues around the anus.

As the abscess drains or progresses, a tract may form connecting the infected cavity to the skin surface. This tract allows persistent drainage of pus, fluid, or occasionally stool. Anal fistulas can take different paths through or around the anal sphincter muscles, making their treatment variable and dependent on the fistula’s anatomy.

Symptoms may include recurrent swelling, pain, discharge of pus or blood, skin irritation, and recurrent infections around the anus.

The diagnosis of an anal fistula is usually made through a combination of clinical examination and imaging studies. Your colorectal surgeon or proctologist may perform:

Visual inspection of the anal region to identify any external openings
Digital rectal examination to assess the fistula tract and detect any internal openings
Anoscopy to examine the anal canal
Endoanal ultrasound or Magnetic Resonance Imaging (MRI) to define the course of the fistula and identify any associated abscesses or secondary tracts. MRI is often the most accurate investigation for mapping complex fistulas and planning treatment

The choice of treatment depends on the location and complexity of the fistula, particularly its relationship to the anal sphincter muscles. The primary goal is to eliminate the fistula while preserving continence. Procedures are usually performed under general or spinal anesthesia.

Fistulotomy

Fistulotomy is the most commonly performed procedure for simple fistulas. The fistula tract is opened along its entire length, allowing it to heal from the inside out. This technique has a high success rate but is generally suitable only when minimal sphincter muscle is involved.

Fistulectomy

Fistulectomy involves complete surgical excision of the fistula tract. This may be recommended in selected cases but can result in a larger wound and longer healing time compared with fistulotomy.

Seton Placement

For complex fistulas involving a significant portion of the sphincter muscle, a seton (a thin surgical thread or drain) may be placed through the fistula tract. The seton helps drain infection, promotes healing, and may be used as a staged treatment before definitive surgery. In some cases, it is left in place long-term to control symptoms while minimizing the risk of incontinence.

FiLaC – Fistula Laser Closure

FiLaC® is a minimally invasive sphincter-preserving technique used for selected anal fistulas. After preparation of the fistula tract, a flexible radial laser probe is inserted into the fistula. Laser energy is then delivered in a controlled manner while the probe is slowly withdrawn, causing the tract to collapse and seal from the inside. The procedure avoids extensive cutting of tissue and aims to preserve the sphincter muscles. The treatment is associated with less postoperative pain and a faster recovery compared with conventional surgery in appropriately selected patients.

Benefits of FiLaC:

Minimally invasive procedure
Maximum preservation of the anal sphincter muscles
Reduced risk of postoperative incontinence
Can be combined with seton drainage or other fistula treatments when required
Usually associated with less pain and faster return to normal activities

In Brief

The treatment of anal fistula is individualized according to the fistula anatomy and patient factors. Most common treatment options include fistulotomy, fistulectomy, seton placement, FiLaC® laser therapy, or a combination of these techniques. The aim of treatment is to eradicate the fistula, prevent recurrent infection, and preserve normal bowel control whenever possible.

Doctors