Use of Intestinal Ultrasound in a Tight Monitoring Approach in Crohn's Disease: A Multicenter Prospective Study

Intestinal ultrasound (IUS) is increasingly used to monitor Crohn's disease (CD) activity, yet its optimal role in tight monitoring strategies remains unclear. We aimed to assess the predictive role of ultrasonographic parameters in determining endoscopic remission (ER) after one year of anti-tumor necrosis factor α, and the correlation of IUS parameters with other outcomes longitudinally.

This was a multicentric prospective longitudinal study enrolling adult patients with active CD starting anti-tumor necrosis factor α. Biomarkers and IUS were performed at baseline, week (W)14, W30, and W54; ileocolonoscopy and magnetic resonance enterography were performed at baseline and W54. The primary outcome was the predictive value of IUS remission (normalization of bowel wall thickness [BWT], stratification, vascularization, and mesenteric fat) for ER at W54 (segmental Simple Endoscopic Score for Crohn's Disease = 0). The International Bowel Ultrasound Segmental Activity Score (IBUS-SAS) optimal cut point to detect ER was identified using receiver operating characteristic analysis.

Sixty-three patients were included, of whom 57 were followed until W54. After 1 year of therapy, 40%, 42%, and 33% achieved endoscopic, IUS, and magnetic resonance enterography remission, respectively. Patients with ER had a significantly lower median BWT and IBUS-SAS score at all time points. The best predictors for ER were IBUS-SAS <56.6 (area under the curve = 0.861) and BWT <2.9 mm (area under the curve = 0.802) at W14. On multivariable analysis, IBUS-SAS <56.6 at W14 was the only independent predictor for ER (odds ratio, 19.0; 95% confidence interval, 1.91-189.6; P = .012).

Early IUS evaluation can noninvasively predict treatment outcomes, supporting its integration into tight monitoring protocols for CD. IUS offers a real-time, cost-effective alternative to endoscopy and imaging, potentially enabling timely therapy optimization to improve patient management.