Intestinal ultrasound measurement of bowel wall thickness can be used as a sole marker for defining anti-TNF maintenance therapy failure in Crohn's disease.

Introduction: Bowel wall thickness (BWT) measurements in intestinal ultrasound (IUS) are recognized indicators of inflammatory activity in Crohn's disease (CD). However, the added value of other ultrasonographic parameters for monitoring and predicting treatment failure during anti-tumor necrosis factors' (TNF) maintenance therapy is still not absolutely defined.

Objectives: To determine whether BWT, as measured by IUS, can serve as a reliable single marker for predicting treatment failure in CD patients under anti-TNF therapy, compared to a combination of ultrasonographic parameters.

Design: This study was a single-center, retrospective cohort study.

Methods: This study included 103 CD patients in clinical remission on anti-TNF therapy, who had an IUS examination within 10 months following therapy initiation. We investigated the correlation of these ultrasonographic parameters with subsequent treatment failures, defined by disease flares, and the need for surgery, hospitalization, corticosteroid use, dose escalation, and drug discontinuation.

Results: Treatment failure occurred in 59.2% of patients within a median of 5 months post-index IUS. Significant differences were observed in BWT (3.9 mm in the failure group vs 3 mm in the remission group, p = 0.007), bowel wall flow (BWF; 49.2% vs 23.8%, p = 0.009), and mesenteric hypertrophy (20.4% vs 7.1%, p = 0.006). In receiver operating characteristic analysis for BWT, the area under the curve (AUC) of BWT >3 mm was 0.66, with a sensitivity of 67.2% and specificity of 69.1%. The combined (BWT, BWF, and mesenteric hypertrophy) AUC was 0.68 (sensitivity of 62.9%, specificity of 61.9%). Delong's test showed no significant difference in AUC (p = 0.137). BWT emerged as the most significant parameter in stepwise regression analysis.

Conclusion: Our findings suggest that BWT alone may be used as a single ultrasonographic marker of treatment, therefore simplifying the use of IUS. Using a single objective ultrasonographic parameter simplifies the use of IUS, an important factor that can facilitate the use of this important imaging technique.