P137 Clinical and pathological correlations between primary and secondary ileal strictures in Crohn’s disease

Abstract Background Ileal strictures requiring surgical resection occurs in 25% of Crohn’s disease (CD) patients. The 10-year risk of recurrence is 44–55%. Pathologically, both primary and secondary strictures exhibit diverse features related to acute and chronic inflammation; however, there is little published data comparing their pathological features pairwise or correlating them with clinical outcomes or stricture recurrence. Methods We retrospectively identified 22 CD patients with ileitis who underwent two resections for strictures >6 months apart. Representative H&E slides of the strictures were reviewed and each layer of the intestinal wall was evaluated semi-quantitatively for the following histological categories: A: structural changes [smooth muscle expansion, neural hypertrophy, adipose tissue, fibrosis]; B: acute inflammatory changes [lymphatic dilation, acute inflammatory cells, oedema, dilated blood vessels]; C: granulomas, and D: lymphoid aggregates. An expert GI pathologist performed analyses, blinded to the clinical data. The presence and severity of each feature was graded 0–3. Mean scores and percentage of maximum total score (PMTS) were determined for each anatomical layer and for the entire intestinal wall section. Two-way unbalanced ANOVA was performed on the paired data. p-Values of