Crohn's Disease Stricture Response to Treatment Assessed with Magnetic Resonance Imaging and Intestinal Ultrasound: STRIDENT Randomized Trial

Abstract

Background: Transmural healing is emerging as a key treatment target in Crohn's disease. This study aimed to determine the role of magnetic resonance imaging (MRI) and intestinal ultrasound (IUS) in the assessment of the radiologic response of Crohn's disease strictures to treatment.

Methods: The STRIDENT (Stricture Definition and Treatment) study was a randomized controlled trial of (2:1) intensive high-dose adalimumab combined with a thiopurine vs standard dose monotherapy adalimumab in patients with stricturing Crohn's disease. Clinical response was defined as a reduction in the Obstructive Symptom Score at 12 months. Intestinal ultrasound was performed at baseline, 4, 8, and 12 months and MRI at baseline and 12 months. This study examines secondary outcomes of stricture resolution and changes in stricture morphology with treatment.

Results: Of 77 patients, 52 were in the intensive treatment group and 25 in the standard therapy group. Clinical response was achieved in 56 of 77 patients (73%). Complete stricture resolution occurred in 17 patients on IUS (29%) and 16 patients on MRI (22%). Stricture improvement occurred in 23 of 59 patients on IUS (39%) and 24 of 72 patients on MRI (33%). Bowel wall thickness improved at 12 months on both IUS (P < .0001) and MRI (P < .001) and was significantly lower in clinical responders (IUS P = .003) and those with fecal calprotectin < 100 µg/g (IUS P < .001; MRI P = .001).

Conclusions: Radiologic severity of Crohn's disease strictures can improve with drug treatment, with complete stricture resolution observed in some. Intestinal ultrasound and MRI are effective modalities for monitoring the treatment response in patients with stricturing Crohn's disease (STRIDENT Drug Therapy Study: NCT03220841).

Keywords: bowel wall thickness; stricturing Crohn’s disease; transmural healing.