Does the Location of the Internal Opening Matter? A Long-term Retrospective Study of the Efficacy of FiLaC ®

Objective The aim of this study was to evaluate the long-term efficacy of fistula laser closure (FiLaC®) in the treatment of cryptoglandular anal fistula. Methods 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. Results 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), 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 subgroups: Parks classification and the treatment of internal orifices. All the 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. Conclusion 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 easy to benefit from this technique.