Risk Factors for Microscopic Disease Positivity at Ileocolic Resection Margins for Crohn's Disease.

Introduction: Interest in microscopic margin positivity during surgical resection of medical-refractory Crohn's disease has been renewed with multiple recent studies showing an association between microscopic margin positivity with disease recurrence. Our aim was to determine risk factors for microscopic margin disease positivity following ileocolic resection (ICR).

Materials and methods: A prospectively-maintained database of patients with Crohn's disease undergoing ICR at a tertiary-referral center was queried. Margin positivity was defined as the presence of cryptitis, erosion, transmural inflammation with lymphoid aggregates, or architectural distortion at either ileal (proximal) or colonic (distal) margins.

Results: Amongst 584 patients, 97 patients had a positive microscopic margin (17%) of which 46% had a positive proximal margin, 17% had a positive distal margin, and 13% had both positive and distal margins. Using multivariable logistic regression analysis, index ICR was associated with less odds of positive margin (odds ratio [OR] 0.46, 95% confidence interval [CI] 0.24-0.89, p=0.02), and granuloma presence was associated with increased odds (OR 2.26, 95% CI 1.23-4.21, p=0.01).

Conclusion: We found that repeat ileocolic resection and granuloma presence were predictors of microscopic margin disease.