Comparison of transmural healing and mucosal healing as predictors of positive long-term outcomes in Crohn’s disease

Background: Transmural healing (TH) is being increasingly recognized for reflecting deep remission in Crohn’s disease (CD). The long-term clinical significance of achieving TH is still not fully known. We aimed to evaluate TH as a predictor of long-term positive outcomes using intestinal ultrasonography (US), with comparison with the established endpoint mucosal healing (MH). Methods: CD patients were consecutively recruited from September 2015 to August 2018 at a single tertiary hospital. All patients were evaluated at baseline and followed up at 6 months prospectively with a guideline-based treatment regimen. Achieving TH/MH or not was evaluated by US/colonoscopy at the first follow-up. Long-term outcomes including steroid-free clinical remission (CR), drug escalation, hospitalization, and surgery, were recorded after at least another 12 months. Results: We identified 77 patients with a median age of 30 years (range, 12–73 years). Twenty-five (32%) patients achieved TH, and 31 (40%) patients achieved MH. TH and MH were poorly correlated (Cohen’s κ = 0.387; p