Treatment of anal fistula with FiLaC: results of a 10-year experience with 175 patients.

Background: Treatment of fistula-in-ano with fistula laser closure (FiLaC) is a sphincter-saving procedure indicated for patients with complex anal fistulas. The aim of our study was to evaluate the clinical results of a 10-year experience with FiLaC.

Methods: Data from patients with cryptoglandular anal fistula who underwent laser closure with FiLaC in June 2009-May 2019 were evaluated. The primary study endpoint was healing rate. Secondary endpoints were evaluation of morbidity and assessment of possible predictive factors of failure.

Results: Out of a total of 180 patients, 5 had been lost to follow-up. 175 patients [m:f: 115:60; median age 49 years (range18-81 years)] with cryptoglandular fistulas treated with FiLaC were included in the study. Fistulas were transphincteric in 152 (86.8%) cases, intersphincteric in 18 (10.3%), and suprasphincteric in 5 (2.9%). A seton or draining silicon loop was placed in 142 (81.8%) patients at a median of 14 weeks (range10-28 weeks) prior to FiLaC. At median follow-up of 60 months (range 9-120 months), the overall primary healing rate was 66.8% (117/175). Thirty-eight patients (21.7%) failed to heal. Twenty out of 175 (11.4%) patients had recurrence at median follow-up of 18 months (range 9-50 months). Patients in whom a seton/loop was inserted for drainage at the first-stage procedure had a statistically significant higher rate of success (100/142, 70.4% vs. 17/33, 51.5%, respectively; p 0.0377; odds ratio 0.45). Forty-eight patients were reoperated on at a median of 15 months (range 12-20 months) after laser treatment. Twenty-six underwent redo laser closure with FiLaC, and 12 of them healed (46%), for a secondary success rate of 73.7%.

Conclusions: Longer follow-up confirms the efficacy of FiLaC in the treatment of complex anal fistulas. Its use and implementation should be encouraged.