P077 Incidence of Colonic Strictures - A Systematic Review and Meta-analysis.

Background: Intestinal strictures are a complication of the inflammatory bowel diseases (IBD, including ulcerative colitis (UC) and Crohn's disease (CD)) that can lead to bowel obstruction and therapy failure. Intestinal strictures occurring after long-standing tissue damage and repair are more frequently reported in CD, but colonic strictures can occur in UC. However, there is a paucity of literature that comprehensively summarizes the available information regarding the incidence and etiology of colonic strictures in UC. The aim of this study was to perform a systematic review and meta-analysis of published reports on the incidence of colonic strictures in UC patients.

Methods: Four independent reviewers performed a comprehensive review of all original articles describing the incidence of colonic strictures in UC published from inception to June 2021. Primary outcomes were (1) overall incidence of colonic strictures; (2) 10-year incidence of colonic strictures; and (3) incidence of colonic strictures containing high-grade dysplasia (HGD) or colorectal cancer (CRC). Subgroup analysis was performed to compare the outcomes between the pre-biologic era and post-biologic era. The meta-analysis was performed and the statistics were 2-tailed. Finally, probability of publication bias was assessed using funnel plots and with Egger's test.

Results: Eleven studies reporting on a total of --- patients with colonic strictures were included in the analysis after comprehensive search. This yielded a pooled colonic stricture incidence rate of 5.4% (95% confidence interval (CI) 3.7-7.8). The incidence rate of colonic strictures was lower in the post-biologic era compared to the pre-biologic era but the difference was not statistically significant (2.6% vs 6%; p = 0.14). The pooled 10-year colonic stricture rate was 3.2% (95% CI 1.5-6.8). The pooled 10-year incidence rate of colonic strictures was lower in the post-biologic era compared to the pre-biologic era but the difference was not statistically significant (1% vs 1.8%; p = 0.1). The pooled incidence of strictures with associated high-grade dysplasia (HGD) or colorectal cancer (CRC) was 21.9% (95% CI 12.2-36.5). The incidence rate of HGD or CRC in colonic strictures was higher in the post-biologic era compared to the pre-biologic era but the difference was not statistically significant (23.6% vs 20.4%; p = 0.79).

Conclusion: This systematic review and meta-analysis on the incidence of colonic strictures in UC showed that the overall pooled incidence and 10-year incidence of colonic strictures in UC are low. There was a trend towards lower incidences of UC strictures in the post-biologic era, although the differences did not reach statistical significance. While the overall incidence of colonic strictures, in UC is low, a high proportion of colonic strictures are associated with HGD or CRC, even in the biologic era. Therefore, this study provides further support for importance of stricture biopsy and surgical evaluation for colectomy in the UC patient with colonic stricture.