S960 High Degree of Variability in Timeline of Indwelling Seton Removal in Perianal Fistulizing Crohn’s Disease

Introduction: Crohn’s Disease (CD) is often complicated by perianal fistulizing disease. Surgical management includes seton placement to promote drainage, treat and prevent abscess formation, and healing. No consensus exists on timing of seton removal or medical therapy. The aim of this study was to determine the variability in the treatment timeline for indwelling perianal setons and their removal in perianal fistulizing Crohn’s disease. Methods: A retrospective review of patients at a tertiary care center from June 2008-May 2021. Patient criteria included luminal diagnosis of CD, diagnosis of perianal fistula, and perianal procedure (n=103). Patients were excluded if lacking luminal Crohn’s disease (n=10), did not undergo seton placement (n=14), had less than one year of follow up (n=14), or had rectovaginal fistula or J pouch (n=2). Sixty-one (61) patients were then assessed for presence of one or multiple setons, and the timeline for presence of seton at 6 months, one year, and greater than 1 year. We utilized logistic regression modeling to assess associations between timeline of indwelling seton and medical therapy. Results: Of 61 patients, the presence of 1 seton (51%) vs multiple setons (49%) was equal. No difference was found in the timeline of seton removal between patients with 1 or multiple setons. Fourteen patients (22.22%) had indwelling setons removed by 6 months, 16 patients (25.39%) had indwelling setons removed by 1 year, and 38 patients (62.3%) had indwelling setons for greater than 1 year. For patients who were on biologics at the time of perianal fistula diagnosis, 8 (28.57%) had seton removal at 6 months, 9 (32.14%) had seton removal at 1 year, and 11 patients (39.28%) had setons in place for longer than 1 year (Figure). The proportion of patients to have seton removal within 1 year was higher if they were on biologics at the time of diagnosis of perianal fistula compared to patients without biologics. No statistically significant associations were found between timeline of indwelling seton and medication exposure. Conclusion: Our patient cohort displays the significant heterogeneity in the timeline patients experience with indwelling setons. We were unable to identify any significant association between medication strategies and the variable timeline for indwelling setons. This variability of seton timeline should prompt formulation of clinical pathways to coordinate multidisciplinary care and define specific treatment strategies to improve the likelihood for seton removal.Figure 1.: Seton Removal and IBD Medication Therapy at Time of Anal Fistula Diagnosis