Use of laser in the treatment of perianal fistulas
(Anorectale fistel laser studie = ArFiLaS)

Perianal fistulas are a common disorder, estimated to occur in 12.3 per 100.000
men and 8.6 per 100.000 woman.
Symptoms caused by a perianal fistula are pain and involuntary loss of gas,
fluids or faeces. Besides these symptoms, complaints of itching and symptoms of
infections are reported. These complaints often result in social embarrassment
and loss of quality of life.

The mucosal advancement flap is considered as one of the best surgical
treatments for high perianal fistula repair. This technique is based on closure
of the internal opening of the fistula tract. In one out of three patients
mucosal flap repair fails. Possible factors for failure are incomplete
clearance of pus and debris, incomplete closure of the internal opening or
other technical failures, or inappropriate host response in patients with risk
factors like smoking of diabetes. Besides a high recurrence rate, the mucosal
advancement flap is also associated with impaired incontinence, rates have been
described as high as 35%.

Laser treatment is a new technique in the treatment for perianal fistulas which
claim to result in none or only minimal damage to the sphincter muscles.
Preliminary results show a closure rate ranging from 71,4% -89%. Until now,
studies are small (n= 11 - 50) and no validated questionnaires were used to
objectively assess continence and quality of life.

Our hypothesis is that treatment of peri-anal fistula with laser ablation is
associated with equal closure rates compared to current therapies.
As secundairy outcome, quality of life, postoperative pain and incontinence
will be assessed.


The primary objective of this study is to investigate the efficacy of laser
treatment in perianal fistula healing.

Primary Question:
What is the healing rate of laser-ablation in high single tract perianal
fistulas?

Secondary Question(s):
Quality of life
Post operative pain
Functional outcome and risk of incontinence

In this prospective multicentre cohort study we will evaluate 100 patients with
high single tract perianal fistulas, who underwent laser ablation.
Hereby we want to evaluate the treatment with laser, it will be a pilot study.
Al patients will receive the same treatment, which consists of a seton
procedure followed by laser-ablation in a secondary procedure.

The primary endpoint of this study is healing rate. The fistula will be
considered healed if the external opening is closed and no discharge or pain or
perianal swelling is experienced. Recurring of these symptoms was defined as a
recurrent fistula. Treatment failure is defined if there is still discharge
coming out of the external opening at 3 months follow-up. Symptoms / visible
fistula at another location are considered as a new primary fistula.
Secondary endpoints are quality of life, postoperative pain and incontinence,
which will be assed using the SF-12 questionnaire, a visual analogue pain seal
(VAS) and the Vaizey and FIQL score.

Follow-up is planned at 6,12, 24 and 52 weeks postoperatively. (fig 3).
Questionnaires are completed preoperatively and during al follow-up moments.

During the follow-up moments an independent colorectal surgeon will examine
patients and determine if the fistula is persistent or healed. In case of doubt
a new MRI-scan will be performed

Laser-ablation of the perianal fistula

No extra risks are expected. However, there is a small risk of infection,
burnwounds or technical failure of the laserfibre (kinking or break down of the
fibre)