Clinical usefulness of EUS for active ulcerative colitis

Background: Ulcerative colitis (UC) is a chronic inflammatory bowel disease with repeated flare-ups. It is difficult to predict the response to medical treatment and the necessity for surgery. Objective: We undertook this study to determine whether EUS is useful for evaluating the depth of intestinal inflammation, predicting the response to medical treatment, and determining the necessity for surgery in active UC. Design: Both the in vivo and in vitro studies used an observational design. Methods: In vitro, the depth of intestinal inflammation on EUS was compared with histopathologic findings in 13 cases of surgically resected UC. In vivo, the severest lesions on colonoscopic examination were evaluated by EUS in 42 patients with active UC to identify US characteristics that indicated the need for surgery. Results: In vitro, the degree of vertical spread of intestinal inflammation of UC on EUS was consistent with histopathologic findings in 45 of 50 sites (90%) studied. In vivo, intestinal inflammation was evaluated to discover whether it extended into the muscularis propria or deeper on preoperative EUS in a significantly higher percentage of patients who required surgery (67%, 10/15) than in patients in whom remission was induced by medical treatment (19%, 5/27; P = .002). Conclusions: EUS can accurately and objectively evaluate the degree of vertical spread of intestinal inflammation in UC. EUS is useful for predicting the response to medical treatment and for determining the necessity for surgery in active UC.