Factors associated with healing, reoperation and continence disturbance in patients following surgery for fistula‐in‐ano

Aim Fistula‐in‐ano (FIA) is associated with high treatment costs and has a deleterious impact on quality of life. A wide range of healing, incontinence and recurrence rates have been reported. This study aimed to identify operative, patient and disease factors that influence these outcomes after surgery for FIA. Method An observational cohort study of consecutive patients who were managed for FIA at a tertiary colorectal practice (1999–2019) was performed. Outcome measures included healing, impaired continence and the need to reoperate. Clinico‐pathological variables, including patient comorbidities, fistula anatomy and operative approach, were assessed for their association with these outcomes. Results Some 411 procedures were performed on 263 patients [median age 41.8 years (range 17.8–79.7 years), 184 men (70.0%)]. Some 77.9% of patients achieved complete healing, 9.5% experienced some deterioration in continence postoperatively and 37.6% required reoperation at a median time of 19.0 weeks. Poorer healing was associated with Crohn’s disease, high trans‐sphincteric fistulas, extrasphincteric fistulas and steroid usage. Poorer continence was associated with female sex, age > 40 years, posterior location, suprasphincteric fistulas, seton insertion and having more than three subsequent procedures. The need to reoperate was associated with female sex, high trans‐sphincteric fistulas, suprasphincteric fistulas, inflammatory bowel disease and previous operations for FIA. Conclusion Minimizing recurrence of FIA and preservation of continence can be competing management goals. More than one in three patients require reoperation, one in five fails to heal completely and one in ten suffers worsened continence following surgery. Awareness of the factors that contribute to these outcomes is important to the process of informed consent and managing patient expectations before surgery.