Prevalence and Risk Factors for Developing Anastomotic Ring Inflammation After Ileal Resection and Ileo-Colonic Anastomosis in Patients With Crohn’s Disease

BACKGROUND: The development of early inflammation proximal to the anastomosis in patients with Crohn’s disease that undergo ileal resection has a significant prognostic significance. However, many patients also develop inflammatory changes at the level of the anastomotic ring. The prevalence and significance of this findings is unknown. The aim of this study is to assess the prevalence and risk factors for developing anastomotic ring inflammation (ARI) in patients with Crohn’s disease after an ileal resection and ileo-colonic anastomosis.

METHODS: In this retrospective cohort study we analyzed 91 patients with Crohn’s disease (CD) who underwent ileal resection and ileocolonic anastomosis and surveillance colonoscopy within 24 months. The patients were followed from time of surgery through up to four subsequent colonoscopes if applicable. A board certified gastroenterologist reviewed all the endoscopic images for the procedures done. The primary outcome was ARI (partial or full).

RESULTS: The cohort population of 91 patients was 51.6% female. Twenty patients had ARI on the first surveillance colonoscopy (4 of the complete anastomotic ring and 16 partial), with an additional 13 developing inflammation at subsequent colonoscopies. The type of surgical anastomosis performed (end to end, end to side or side to side) was not associated with the development of ARI (P > 0.05 for all). There was no difference in time between bowel resection and endoscopic assessment between those patients with and without ARI (12 [IQR: 7-26] and 11 [IQR: 8-18] months respectively [P = 0.62]). There were no differences in median Rutgeerts score or simple endoscopic score (SES-CD) in patients that did present with ARI versus those who did not (median Rutgeerts score of 1 [IQR: 0-2] and 0 [IQR: 0-2] [P = 0.37], and median SES-CD of 2 (IQR: 0-3] and 0 [IQR: 0-4] respectively [P = 0.52]). There was also no association between the presence of ARI and active histologic inflammation in the ileum proximal to the anastomosis (P = 0.23). There was also no statistically significant difference in age at the time of surgery between those patients with and without ARI (median of 35 [IQR:28-42] and 36 [IQR: 27-52] years respectively [P = 0.7]). Starting post-operative prophylaxis for CD recurrence was not associated with a lower prevalence of ARI (OR: 0.26 [95% CI: 0.03-2.1]. P = 0.18).

CONCLUSION(S): No demographic or phenotypic variables were associated with development of inflammatory changes at the level of the anastomotic ring. Furthermore, the presence of inflammation did not correlate with endoscopic CD disease activity. Studies looking into the long term clinical significance of ARI are warranted.