Anal fistula is one of the most frequent anorectal disorders. Although most fistulas are simple and can be easily resolved by fistulotomy or fistulectomy, some cases are complex and constitute a real challenge for the surgeon, as continence must be preserved while the suppurative process is eradicated.

Advanced laser fistula ablation (ALFA™; neoLaser, Caesarea, Israel) is a new sphincter-saving procedure that involves intermittent thermal ablation of the fistula tract. A radial emitting optical fiber is used for laser energy delivery to destroy the epithelium lining inside the fistula tract and to induce obliteration of the remaining tract via a shrinkage effect.

First studies reported promising outcomes with overall healing rates of 70–80% [1, 2]. However, most of them were retrospective case series of a limited number of patients. Most recent studies have showed poorer outcomes with overall healing rates of 33–45% [3,4,5]. In the attached video, ALFA™ is performed in a 42-year-old male with a middle transsphincteric right posterior perianal fistula diagnosed with 3D endoanal ultrasound. The ALFA ™ was chosen as a minimally invasive, sphincter-saving procedure considering the transphincteric pathway of the fistula tract, the length of the fistula tract (shorter than 4 cm) and the absence of undrained collections or cavities because of our personal experience of success in fistula with similar characteristics. Fistula tract catheterization was eased by sheathing the metal probe in a previously sectioned tube. Then, the metal probe was withdrawn and the laser fiber was introduced until the tip protruded through the internal fistula opening. Finally, the aspiration tube was removed, and the laser system was activated.