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Updated: Sep 15, 2025

Murine Ileocolic Bowel Resection with Primary Anastomosis
Published on: October 29, 2014
Isolated Anastomotic Ulcers Are Associated with a Higher Long-Term Risk for Postoperative Recurrence and a
Michiel Thomas Jan Bak1,2,3, Pablo Andres Olivera1,2, Cristian Hernandez-Rocha1,2
1Zane Cohen Centre for Digestive Diseases, Lunenfeld-Tanenbaum Research Institute, Sinai Health System, 60 Murray St, Toronto, ON M5T 3L9, Canada.
Background:
The clinical relevance and underlying mechanism of isolated anastomotic ulcers (IAUs) following ileocolic resection (ICR) in patients with Crohn's disease (CD) are poorly understood. This study aimed to assess the postoperative recurrence (POR) risk and the mucosa-associated microbiome composition in CD patients with or without IAUs among those with a healthy neo-terminal ileum (TI).
Methods:
CD patients who underwent ICR and without any ulcerations in the neo-TI (SES-CD ≤2) at first postoperative ileocolonoscopy were identified from an ongoing prospective multicenter study. The primary study outcome was time to POR measured from the first postoperative ileocolonoscopy. Cox proportional hazard models were used to assess the association of IAUs with time to POR. The mucosa-associated microbiome at first ileocolonoscopy was assessed by sequencing the 16S rRNA gene using biopsies taken from both sides of the anastomosis.
Results:
Sixty patients were included, of whom 27 patients had IAUs (45.0%) at first ileocolonoscopy. Median time to first postoperative ileocolonoscopy was 6.5 months (interquartile range [IQR] 5.3-8.1). During a median follow-up duration of 3.0 years (IQR 1.4-5.5) after first postoperative ileocolonoscopy, POR was observed in 53.3%. After adjustment for clinical risk factors, IAUs were independently associated with POR (adjusted hazard ratios 5.4; 95% CI 2.4-12.4; P < .001). At the ileal and colonic side of the anastomosis, a significantly higher abundance of Klebsiella was associated with IAUs (q < 0.05).
Conclusions:
IAUs in CD patients with otherwise healthy neo-TI at first postoperative ileocolonoscopy are associated with long-term POR. In addition, a differential mucosa-associated microbiome composition was observed in patients with IAUs, specifically the proteobacteria Klebsiella, suggesting that putative taxa are related to these lesions. Further validation studies in larger cohorts, along with mechanistic studies, are still required.
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