Toward transmural healing: Sonographic healing is associated with improved long-term outcomes in patients with...

Transmural healing has emerged as a treatment target in Crohn's disease (CD). We investigated whether transmural healing assessed with intestinal ultrasound (IUS) is associated with improved clinical outcomes in patients with CD in clinical remission.

Patients with CD in clinical remission at baseline (HBI <4) having IUS between August 2017 and June 2020 with at least 6-months' follow-up were retrospectively studied. Time to medication escalation, corticosteroid use and CD-related hospitalisation or surgery were compared by the presence or absence of sonographic healing, defined as bowel wall thickness ≤3 mm without hyperemia on color Doppler, inflammatory fat, or disrupted bowel wall stratification. Factors associated with survival were analyzed by Kaplan-Meier analysis using Cox proportional-hazard model.

Of 202 consecutive patients (50% male), sonographic inflammation was present in 61%. During median follow-up of 19 (IQR 13-27) months, medication escalation occurred in 52%, corticosteroid use in 23%, hospitalisation in 21%, and CD-related surgery in 13%. Sonographic healing was significantly associated with a reduced risk of medication escalation (p = 0.0018), corticosteroid use (p = 0.0247), hospitalisation (p = 0.0102), and surgery (p = 0.083). On multivariable analysis, sonographic healing was significantly associated with an increased odds of medication escalation-free survival (hazard ratio [HR]:1.94; 95% CI 1.23-3.06; p = 0.004) and corticosteroid-free survival (HR:2.41; 95% CI 1.24-4.67; p = 0.009), but not with hospitalisation or surgery.

In patients with CD in clinical remission, sonographic healing is associated with improved clinical outcomes. Further studies are needed to determine whether sonographic healing should be a treatment target.