Is transmural healing better than mucosal healing in pediatric Crohn's disease?

Background: Limited data exist on the long-term benefits of transmural healing (TH) in pediatric Crohn's disease (CD). Aims: To evaluate outcomes children with CD achieving TH compared to those with mucosal healing (MH) and no healing (NH). Methods: Retrospective, single-center study including children with CD undergoing magnetic resonance enterography (MRE), ileocolonoscopy, and/or capsule endoscopy within a three-month interval. TH was defined as mucosal healing on endoscopy and bowel wall healing on MRE. MH as normal ileocolonoscopy with active findings on MRE. NH included active endoscopic disease irrespective of MRE results. Outcomes assessed at 6, 12 and 24 months included hospitalizations, surgeries, treatment escalation and complications. Results: Ninety-three children (12 years, 2-17) were included: 23 TH (25 %), 27 MH (29 %) and 43 NH (46 %). Compared to NH, both TH and MH had lower risk of treatment escalation (p < 0.0001 and p = 0.0002, respectively), but only TH was associated with a lower risk of hospitalization (p = 0.02) and complications (p = 0.007). No significant differences were observed between TH and MH regarding all the outcomes. The risk of surgery was comparable across the three groups. Conclusion: Achieving TH improves outcome in children with CD, although the additional benefit over MH alone is limited. The persistence of inflammation is associated with worse outcomes in all patients.