Laser Assisted Treatment of Fistula In Ano (LATFIA)

LATFIA-trial: Laser Assisted Treatment of Fistula In Ano Randomized Controlled Trial Comparing FiLaCTM to Rectal Advancement Flap

Randomised Controlled Trial comparing Laser assisted closure of transsphincteric fistula to the rectal advancement flap.

A prevalent and complex fistula type is the high transsphincteric (TS) fistula. It typically runs through the upper two-thirds of the external anal sphincter (EAS) and is, due to the high risk of fecal incontinence, not suitable for fistulotomy and sphincter sparing treatment is required. To be included in this trial the participants should have a single, continuous TS fistula of cryptoglandular origin, that is treated by loose seton drainage for at least 2 months and is mapped by MRI. Participants with IBD, hidradenitis suppurativa or a malignant fistula will be excluded. Intervention Fistula Laser Closing (FiLaCTM) (Biolitec, Germany) is an endofistular technique, using a radial-emitting laser fiber that emits laser light with a maximum penetration depth of 2 - 3 mm. It destroys both the crypt gland and the additional epithelial layer of the fistula without damaging the sphincter. The fiber is inserted until the internal opening, activated and pulled backwards slowly, allowing the laser to have its effect. The external opening is excised and the internal opening is closed with a single absorbable suture. Rectal advancement flap is currently the gold standard for sphincter sparing treatment of high transsphincteric fistulae. The fistula is cored out and an advancement flap is made of mucosa and submucosa. The opening of the fistula in the flap is excised, the residual internal opening is closed with absorbable suture and the flap is sutured below the fistula to the anoderm. The advancement flap is a difficult technique that requires a relatively large transanal dissection that results in postoperative pain and may lead to disturbances in continence. Preliminary results with the Filac technique show fistula healing rates comparable to the advancement flap. Due to its simplicity, speed and minimal invasiveness the investigators expect a benefit for the participants in terms of postoperative pain, operating time and quality of life.

Success rate (number of patients) of laser/flap treatment defined as full healing (fistula closure) after the index procedure

Secondary success rate (number of patients) defined as full healing (fistula closure) after a second procedure (either rectal advancement flap, laser treatment, fistulotomy)

Reported pain after laser or flap treatment: measured using the visual analog scale - VAS where 0 = no pain; 10 = worst pain imaginable,

Reported fecal incontinence after laser or flap treatment: measured using the Vaizey score where minimum score 0 = perfect continence; maximum score 24 = totally incontinent)

Reported wound complications after laser or flap treatment defined as wound dehiscence or bleeding as reported on the adverse event forms

General postoperative well being and ability to partake in daily life and daily tasks (specific role functioning) measured and scored using the SF 36 questionnaire (consisting of 8 weighted scales: vitality, physical functioning, bodily pain, general health perceptions, physical role functioning, emotional role functioning, social role, functioning, and mental health. The lower the score the more disability. The higher the score the less disability) This outcome is measured in all participants after the initial procedure (index flap or laser treatment) as well as after a second procedure (in case of recurrence)

Number of participants presenting with a clinical recurrence or residual fistula after initial and laser/flap treatment (index procedure)

Number of participants presenting with a clinical recurrence or residual fistula after the second procedure (Laser - Flap - Fistulotomy - Ligation of the fistula tract, video-assisted fistula treatment)

This outcome evaluates the correlations between patients'/ fistula's clinical characteristics and primary healing rates

Inclusion Criteria: Patients with fistula involving more than one-third of the external anal sphincter Single, continuous fistula tract at time of inclusion Loose seton present in fistula tract for 2 months or more at time of inclusion Age ≥ 18 Able to complete an informed written consent, understand its implications and contents, and participate in follow-up Exclusion Criteria: Fistula tract < 1 cm Complex fistula tract system (branching of fistula tract inside the sphincter complex) Pregnancy HIV-positive Crohn´s disease, Ulcerative colitis Fistula due to malignancy Tuberculosis Hidradenitis Suppurativa No internal opening Unable to undergo or contraindications to MRI