Purpose: Acute mesenteric ischemia is associated with high rates of morbidity and mortality and requires emergent treatment. Patients are critically ill, usually with severe co-morbidities and management may depend on the viability of bowel loops, as diagnosed by the radiologist. The aim of this study was to identify CT features that may distinguish between viable and necrotic bowel in mesenteric ischemia.
Materials and methods: A computerized search for consecutive patients that underwent surgery for mesenteric ischemia and had a CT angiography prior to surgery was conducted for the years 1/2012 – 7/2015. Two radiologists blinded to clinical data and surgery results, retrospectively analyzed in consensus all CT examinations with respect to the following imaging features bowel wall, enhancement, bowel dilatation, pneumatosis intestinalis, mesenteric stranding and free fluid. Specificity and sensitivity of each imaging feature for necrosis were calculated. Associations between viable and necrotic bowel in surgery and imaging features were evaluated (Fisher’s exact test).
Results: Twenty-four patients were included. Intestinal necrosis was seen in 14/24 (58.3%) patients. Specificity for necrosis was high for all investigated imaging features (non-enhancement of bowel wall 90.0%, increased bowel wall enhancement 100.0%, bowel dilatation 80.0%, pneumatosis intestinalis 100.0%, mesenteric stranding 90.0%, and free fluid 100.0%). High sensitivity for necrosis was seen only for bowel dilatation and mesenteric stranding (non-enhancement of bowel wall 21.4%, increased bowel wall enhancement 21.4%, bowel dilatation 78.6%, pneumatosis intestinalis 14.3%, mesenteric stranding 92.9%, and free fluid 28.6%). Only bowel dilatation (p=0.011) and mesenteric stranding (p=0.002) were significantly associated with necrosis.
Conclusions: While the presence of all investigated features suggest necrosis, only the absence of bowel dilatation and absence of mesenteric stranding suggest viable bowel, as those features have high sensitivity for necrosis. This data may help surgeons when making clinical decisions.
