Treatment of complex perianal fistulas with fistula laser closure : Application of the IDEAL 2A framework.

AIM: Fistula laser closure (FiLaC) is a minimally invasive treatment option for perianal fistulas with acceptable healing rates. We report implementation and include short-term results in line with the IDEAL (Idea, Development, Exploration, Assessment, Long-term study) 2A framework in patients with complex fistulas and previous surgical repair attempts. METHOD: Prospective audit data from 56 consecutive patients with perianal fistulas treated between June 2024 and January 2025. The FiLaC procedure included cleaning the fistula tract, application of approximately 100 J/cm fistula length and closing of the internal opening with a stitch. All patients refused more invasive operations and/or were not suitable for advanced repair. RESULTS: Patients were diagnosed with fistulas after a median of 34.5 months (interquartile range, IQR 13.8-54.2 months), with a median of 3 months (IQR 1.8-4.0 months) following previous fistula-related surgery. Most patients had cryptoglandular fistulas (80.4%) while 19.6% had inflammatory bowel disease-related fistulas. Most fistulas were transsphincteric (69.6%), and only 32.1% of patients were seton-free before the procedure. During the first postprocedural outpatient visit at 7.9 weeks (median; IQR 6.4-10.9 weeks), clinical healing was evident in 14 (24.1%) cases, and 23 (39.7%) patients reported relevant symptomatic improvement. A total of 21 patients (36.2%) did not report any improvement, 3 patients (5.2%) experienced a postoperative complication, with 1 (1.7%) requiring a return to theatre due to an abscess. After a median of 10.4 months, the "seton-free rate" was 67.9%, This represents a relevant improvement to 32.1% before FiLaC. CONCLUSION: The use of FiLaC is a safe, sphincter-preserving treatment for complex perianal fistulas and was associated with a marked increase in the seton-free rate. While complete fistula healing rates were lower than previously reported, FiLaC remains an option for patients with complex disease.