Fistulectomy and primary sphincteroplasty in complex anal fistula treatment: a hospital-based long-term follow-up study

Background Currently, there is no agreement on the best treatment for complex anal fistulas with the least recurrence and lowest complication rate. The aim of this study was to evaluate the long-term recurrence and incontinence after fistulectomy and primary sphincteroplasty (FIPS) in a group of patients with complex perianal fistula. Methods This prospective observational study was done at the colorectal ward of Taleghani Hospital of Tehran from January 2010 to December 2020. Patients with anal fistula who underwent FIPS were studied. After surgery, patients were evaluated regularly by a colorectal surgeon for fistula recurrence and incontinence. Recurrence was described as a new fistula tract formation after the initial cure and failure of healing in the operation site or any purulent discharge from the fistula tract and openings. In addition, the patient's continence was assessed based on the Wexner score. Results There were 335 patients (66 men and 269 women, mean age 42.74 +/- 12.44 years), 191 of them with low fistula and 144 with high fistula. Thirteen patients (3.90%) experienced recurrence (all had a low fistula). Thirty-nine patients (11.64%), 19 patients with high and 20 patients with low fistula, had a Wexner score >= 3 during the follow-up. Fifteen patients were lost to follow-up. Male patients (OR = 2.67, 95% CI 0.84, 8.45, p = 0.094, adjusted OR = 4.41, 95% CI 1.05, 18.48, p = 0.042), patients with low fistula (p = 0.001), and recurrent cases had a significantly higher rate of recurrence (OR = 10.38, 95% CI 3.24-33.20 p <= 0.001, adjusted OR = 23.36, 95% CI 4.35-125.39, p <= 0.001). A significant correlation between body mass index > 35 kg/m(2) and incontinence was found (OR = 4.40, 95% CI 1.35, 14.33, p = 0.014). Conclusions In the present study, an acceptable healing rate and a low percentage of complications following FIPS were seen in patients with complex anal fistula. Randomized clinical trials with appropriate follow-up duration and sample size comparing different surgical methods in these patients are needed to confirm these results.