Does the location of the internal opening matter? A long-term retrospective study of the efficacy of FiLaC®

The aim of this study was to evaluate the long-term efficacy of fistula laser closure (FiLaC®) in the treatment of cryptoglandular anal fistula. Data from Parks I-II cryptoglandular anal fistula patients in Parks I-II who underwent FiLaC® in our department between September 2017 and December 2019 were retrospectively analyzed. Demographic data, perioperative data, and postoperative data were collected and statistically analyzed. A total of 52 patients were included in the study. The success rate at 3 months, 1 year, and 5 years was 76.9% (40/52), 75% (39/52), and 71.2% (37/52), respectively. The differences between the internal orifice location subgroups were statistically significant (P = 0.013), with the anterior type demonstrating a lower success rate than the bilateral and posterior types. No statistically significant differences were observed between the subgroup of Parks classification and the treatment of internal orifices. All scores, including visual analogue scale pain score (VAS-PS), Cleveland Clinic Florida Incontinence Score (CCF-IS), and the quality of life in patients with anal fistula questionnaire score (QoLAF-QS), showed no obvious difference. FiLaC® technique can significantly relieve postoperative pain, reduce the incidence of anal incontinence and improve the postoperative quality of life in long-term follow-up. Patients with bilateral and posterior anal fistula are more likely to benefit from this technique.