Correlation between the macroscopic severity of Crohn's disease in resected intestine and bowel wall thickness evaluated by water-immersion ultrasonography.

ABSTRACT

Objectives: Transabdominal ultrasonography is a common and accurate tool for managing Crohn's disease (CD); however, the significance of the resulting data is poorly understood. This study was performed to determine the association between bowel wall thickness evaluated by water-immersion ultrasonography and macroscopic severity, namely, refractory inflammation and subsequent fibrosis in CD surgical specimens.Materials and methods: We retrospectively evaluated 100 segments of colon and small intestine from 27 patients with CD. The resected specimens were placed in saline postoperatively, and bowel wall thickness was measured by water-immersion ultrasonography and compared with macroscopic findings. Correlations between bowel wall thickness and macroscopic findings were assessed using analysis of variance and receiver operating characteristic curves.Results: According to the progression of macroscopic severity, the mean bowel wall thickness was increased as follows macroscopically intact 4.1 mm, longitudinal ulcer scars 5.4 mm, longitudinal open ulcers 6.0 mm, large ulcers 6.4 mm, cobblestone-like lesions 7.1 mm, and fibrotic strictures 7.4 mm. For all lesions except longitudinal ulcer scars, the bowel wall thickness was significantly thicker than that of macroscopically-intact areas (p < .001). According to receiver operating characteristic curves, bowel wall thickness >4.5 mm was associated with CD lesions, and thickness >5.5 mm was associated with more severe lesions.Conclusions: The bowel wall thickness of CD lesions was evaluated by water-immersion ultrasonography correlated with macroscopic disease severity.