The following is a summary of “A combination of bowel wall thickness and submucosa index is useful for estimating endoscopic improvement in ulcerative colitis: external validation of the Kyorin Ultrasound Criterion,” published in the January 2024 issue of Gastroenterology by Komatsu, et al.
Endoscopic improvement (EI), a Mayo endoscopic subscore of 0 or 1, is a crucial therapeutic goal in managing ulcerative colitis (UC). Intestinal ultrasound (IUS) offers a non-invasive approach to estimating EI, presenting an advantage over traditional endoscopy. Previously, a novel sonographic parameter, the submucosa index (SMI), was developed as the ratio of submucosal thickness to bowel wall thickness (BWT). Combining BWT and SMI yielded a practical criterion, the ‘Kyorin Ultrasound Criterion for UC’ (KUC-UC), which showed promise in estimating EI without color Doppler assessment. For a study, researchers sought to validate the EI estimation ability of KUC-UC using an external cohort.
The study included patients with UC who underwent both IUS and colonoscopy within 15 days without alterations in treatment between examinations. IUS findings were evaluated, including BWT, SMI, and the modified Limberg score for colonic vascularity.
Analysis of 44 test pairs of IUS and colonoscopy examinations in 122 colonic segments revealed that KUC-UC demonstrated a positive predictive value (PPV) of 94.6% and a negative predictive value (NPV) of 80.0% for EI. The standard criterion of BWT < 3 mm showed PPV and NPV of 85.4% and 79.0%, respectively, while the validated Milan Ultrasound Criteria (a score of ≤ 6.2) exhibited PPV and NPV of 83.0% and 82.7%.
External validation confirmed that KUC-UC, utilizing only B mode findings without complex calculations, served as a feasible and accurate sonographic criterion for estimating EI in UC.
Reference: link.springer.com/article/10.1007/s00535-024-02077-z