Transmural Remission Rate Assessed by Intestinal Ultrasound in Crohn’s Disease Patients with Endoscopic Remission

Abstract

Objective: This study aimed to evaluate the intestinal ultrasound (IUS) findings in Crohn’s disease (CD) patients who achieved endoscopic remission (ER) and to compare the clinical and treatment-related features between patients with and without ultrasound remission (UR).

Methods: Endoscopic remission was defined as a Simple Endoscopic Score for CD ≤2 in each intestinal segment. Bowel wall thickness (BWT), color Doppler signal (CDS), bowel wall stratification, and mesenteric fat inflammation were assessed. International Bowel Ultrasound Segmental Activity Score (IBUS-SAS) and Bowel Ultrasound Score (BUSS) scores were calculated. Ultrasound remission was defined as IBUS-SAS score below 25 or as BUSS score below 3.52 in each segment. Transmural activity was defined as the absence of ultrasound remission, i.e., the presence of at least 2 intestinal segment exceeding the aforementioned thresholds.

Results: Among 24 patients in ER, transmural activity was detected in 7 patients (29.2%) using IBUS-SAS, while only 1 patient (4.2%) was positive according to BUSS. When BWT alone was used as the marker of transmural activity, 4 patients (16.7%) were classified as not achieving TR, including 1 patient with an IBUS-SAS score below the activity threshold. When transmural activity was defined as the combination of BWT ≥3 mm and CDS ≥1, only 1 patient (4.1%) met the criteria. Perianal disease was observed more frequently in patients without UR compared to those achieving UR (42.9% vs. 5.9%), although this difference did not reach statistical significance. Similarly, the rate of biologic treatment and the duration of therapy were higher among patients without UR again without attaining statistical significance.

Conclusion: Nearly one-third of CD patients in ER may have residual transmural activity detectable by IUS. Persistent inflammatory burden, such as perianal disease, may delay transmural healing despite mucosal remission.

Cite this article as: Eşkazan T, Ceylan G, Alasgarlı S, et al. Transmural remission rate assessed by intestinal ultrasound in Crohn’s disease patients with endoscopic remission. Cerrahpaşa Med J. 2026, 50, 0034, doi: 10.5152/cjm.2026.26034.