Long-term healing after complex anal fistula repair in patients with Crohn’s disease

Complex anal fistula in Crohn’s disease (CD) poses a challenging problem. We sought to evaluate long-term surgical healing of complex anal fistula in CD through the two robust repair options—ligation of the intersphincteric fistula tract (LIFT) and advancement flap (AF).

A single-center retrospective study was conducted evaluating long-term healing rates in patients with CD with complex anal fistula undergoing LIFT or AF in 2008–2018. Fistula healing was defined as closure of external wounds, cessation of drainage and absence of pain. Short-term and long-term healing rates were compared. Cox proportional hazards model was performed to identify independent predictors of fistula healing.

The study cohort included 60 CD patients undergoing LIFT (n = 38) or AF (n = 22). The AF group included 8 dermal flaps. Patients having LIFT were younger (35 years vs 43 years; p = 0.007), more likely to have a seton at the time of repair (92% vs 68%; p = 0.03) and less likely to have had prior repair attempts (34% vs 68%; p = 0.02). Short-term fistula healing occurred in 65% (n = 39) of the overall study cohort. However, at final follow-up, median 36 months (range 6–192 months), only 46% (n = 28) of repaired fistulas were healed. Considering the overall status of the cohort’s perianal health at final follow-up, including both repaired, secondary or novel anal fistulas, only 50% (n = 30) of all patients in the cohort had all fistula sites healed and maintained bowel continuity at final follow-up. On Cox proportional hazards analysis, LIFT independently predicted long-term fistula healing (hazard ratio 2.3; 95% confidence interval 1.1–4.9; p = 0.03). Only a small number of patients (n = 5; 8%) required fecal diversion (n = 3) and/or proctectomy (n = 2).

Repair of complex anal fistula in CD results in modest healing rates. LIFT independently predicts long-term healing. However, these results must be taken in context, considering differences in patient and fistula characteristics between groups. These results ought to be kept in mind when counseling CD patients with complex anal fistula.