Protocol of the LATFIA trial (Laser Assisted Treatment of Fistula in Ano): a multicentre, prospective, randomized controlled trial comparing fistula-tract laser closure (FiLaC™) with rectal advancement flap for high trans-sphincteric fistulas.

AIM: Anal fistula is one of the most common anal diseases, affecting between 1 and 3 per 10 000 people per year. Symptoms have a potentially severe effect on a patient's quality of life. Surgery is the mainstay of treatment, aiming to cure the fistula and preserve anal sphincter function. Rectal advancement flap (RAF) is currently the gold standard treatment but has recurrence rates varying between 20% and 50% and might lead to disturbance of continence. The aim of the trial described in this work is to discover if the minimally invasive fistula tract laser closure (FiLaC™) technique could achieve higher healing rates and a better functional outcome than RAF.

METHOD: We will perform a randomized prospective multicentre noninferiority study of the treatment of high trans-sphincteric perianal fistulas, comparing FiLaC™ with RAF in terms of fistula healing, recurrence rate, functional outcome and quality of life. Primary and secondary fistula healing will be evaluated at 26 and 52 weeks' follow-up. Quality of life will be evaluated using the SF-36 questionnaire, the Faecal Incontinence Quality of Life Scale questionnaire and the Vaizey score at 3, 6, 12 and 26 weeks postoperatively.

CONCLUSION: High trans-sphincteric fistulas have a potentially severe effect on a patient's quality of life. Classical treatment with RAF is a time-consuming invasive procedure. The LATFIA trial aims to compare FiLaC™ with the gold standard treatment with RAF. In case of noninferiority, FiLaC™ treatment could be standardized as a first line treatment for high trans-sphincteric fistulas. Better conservation of the patient's anal sphincter function could possibly be obtained. Likewise, we will report on the postoperative quality of life when applying these two techniques.