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 1 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.