Bowel wall thickness at abdominal ultrasound and the one-year-risk of surgery in patients with Crohn's disease

OBJECTIVES: Abdominal ultrasound can assess the extent and localization of Crohn's disease, and an increased bowel wall thickness is the most common finding. Our aim was to correlate bowel wall thickness at ultrasound, with the risk of short-term surgical outcome in patients with Crohn's disease. MATERIALS AND METHODS:From 1997 to 2000 we performed ultrasound in 174 consecutive patients with Crohn's disease. Surgical operations were recorded over a 1-yr follow-up. Logistic regression analysis was performed to identify clinical and ultrasound risk factors for surgery. RESULTS: Fifty-two patients underwent surgery within 1 yr. Indication for surgery was strictures in most of the cases. Median bowel wall thickness was higher in patients with surgery (8 mm) than those without surgery (6 mm) (p < 0.0001). A receiver operating characteristic (ROC) curve was constructed taking into account bowel wall thickness for selecting patients with a high risk of surgery. The optimized cut-off for equally important sensitivity and specificity was calculated at 7.008 mm. The binary regression analysis showed that CDAI > 150, absence of previous surgery, stricturing-penetrating pattern, the presence of intestinal complications, and intestinal wall thickness >7 mm were associated with an increased risk of surgery. Patients with intestinal wall thickness >7 mm at ultrasound had the highest risk (OR: 19.521, 95% CI: 5.362-71.065). CONCLUSIONS: Data suggest that bowel wall thickness >7 mm at ultrasound is a risk factor for intestinal resection over a short period of time. Routine use of abdominal ultrasound during evaluation of patients with Crohn's disease may identify a subgroup that is at high risk for surgery.