Management of perianal fistula in inflammatory bowel disease: identification of prognostic factors associated with surgery

Purpose As one of the clinical manifestations of inflammatory bowel disease (IBD), perianal fistula disease (PFD) can potentially impact the patient quality of life. The management of PFD employs a multidisciplinary approach which includes antibiotics, biological therapies, immunomodulators, and surgery. We analyzed the outcome and prognostic factors of anal fistula surgery in IBD patients. Methods We conducted a retrospective study of IBD patients undergoing elective surgery for anal fistula between January 2015 and December 2018 at our University Department of Surgery. We collated demographic factors, disease activity, imaging (MRI and endoanal ultrasound), surgical interventions, and medical treatment assessing the rate of fistula closure and fecal incontinence, 2 months and 1 year after surgery. Results Thirty-five IBD patients with anal fistula underwent surgery (28 Crohn's disease, four ulcerative colitis, and three indeterminate colitis). Twenty-seven patients presented with complex fistulas and eight with simple fistulas with 10 patients undergoing single-stage surgery. In 25 patients, a two-stage surgical approach was planned and performed (draining seton plus medical treatment and then second-stage surgery with curative intent). At 1 year of follow-up, the fistula healing rate was 50% for single-stage surgery and 60% for two-stage surgery (P = 0.09). Overall, 19.2% of patients developed postoperative fecal incontinence. A time interval greater than 12 months between surgeries is a favorable prognostic factor for fistula healing with the two-stage approach (P = 0.002). Conclusions In our retrospective study, two-stage surgery in IBD patients presenting with complex perianal fistulous disease results in a better medium-term outcome with a longer time interval between surgeries.