BACKGROUNDFistula-tract laser closure (FiLaC™) has shown promising outcomes in perianal fistulizing Crohn's disease (pfCD). However, most studies assessed a mixed cohort encompassing pfCD and cryptoglandular fistulas during a short follow-up period. This study aimed to evaluate the long-term treatment outcomes of FiLaC™ in patients with complex pfCD.METHODSData from patients with complex pfCD who underwent FiLaC™ during deep remission of Crohn's disease between January 2019 and December 2020 were retrospectively analyzed. Patient demographics, surgery history, and medication strategy were registered before surgery. Follow-ups were scheduled at 1, 2, and 3 months after FiLaC™, and at 2-month intervals thereafter. The primary endpoint was clinic healing, while clinic remission/unhealed/recurrence were classified as unhealed. Additionally, adverse events and Wexner fecal incontinence score were documented.RESULTSForty-nine patients (40 men and 9 women) with a median age of 26.0 (19.0-35.5) years were included with a median follow-up of 50.0 (39.5-54.0) months. Of these, 31 (63.3%) patients achieved fistula healing, 3 (6.1%) experienced improvement, 3 (6.1%) remained unhealed, and 12 (24.5%) experienced recurrence. Montreal A category was lower in the healed group (P < 0.001). No major complications, such as bleeding or fecal or urinary incontinence, were observed, and pain was transient. The Wexner incontinence score decreased significantly at the last available follow-up, indicating an intact postoperative continence function (P = 0.014). PCDAI scores were significantly higher in the unhealed group (P = 0.041).CONCLUSIONFiLaC™ is an efficient and safe sphincter-saving procedure for patients with complex pfCD.