Clinical course of distal ulcerative colitis in relation to appendiceal orifice inflammation status

Background: Although appendiceal orifice inflammation (AOI) is frequently observed as a skip lesion of ulcerative colitis (UC), its clinical significance is not clearly understood. We aimed to evaluate whether AOI is associated with the clinical course of UC. Methods: Ninety-four patients with newly diagnosed distal UC were prospectively enrolled at the Asan Medical Center between March 1996 and October 2002. Clinical features and colonoscopic findings during the follow-up period were analyzed in relation to initial AOI status. Results: Forty-eight patients were found to be initially AOI-positive and 46 to be initially AOI-negative. We found no difference in the baseline demographics and clinical characteristics between these two groups. The median follow-up periods for AOI-positive and AOI-negative groups were 45 and 41 months, respectively Clinical remission was achieved in all patients of each group. The cumulative risk of relapse at 1, 3, and 5 years after remission was 31.2% 59.8%, and 69.2%, respectively, in the AOI-positive group and 17.4% 46.5%. and 67.2%, respectively, in the AOI-negative group (P = 0. 124). The Cumulative risk of proximal disease extension at 1, 3, and 5 years after diagnosis was 17.9%, 24.9%, and 44.5%, respectively, in the AOI-positive group and 9.8%, 21.5%, and 43.9%, respectively, in the AOI-negative group (P = 0.522). Proctocolectomy was performed in no patients in the AOI-positive group and in I patient in the AOI-negative group. No mortalities were observed in either group. Conclusions: in patients with distal UC, AOI may have no prognostic implications in terms of remission, relapse, or proximal disease extension.