The Bottom Line: Multidetector CT is a powerful tool for the assessment of patients with SBO. CT can provide important information about the cause and site of obstruction and the presence of a closed-loop obstruction or ischemia.
Summary: The ability to identify patients who will fail conservative management despite the absence of an acute abdomen at presentation may result in better outcomes for these patients. To this end, multivariate predictive models combining imaging findings, laboratory results, and clinical findings have been developed to identify those patients requiring surgery earlier in their presentation. In a study by Schwenter and colleagues, the clinical factors of pain, guarding, leukocytosis, and elevated C-reactive protein were combined with reduced wall enhancement and greater than 500 mL of free fluid on CT into a scoring system. The presence of 3 factors yielded specificity of 91% and sensitivity of 68% for surgical resection of ischemic bowel within 24 hours in comparison with successful conservative management. With 4 factors present, the specificity was 100%. Zielinski and colleagues found that patients with SBO who presented with lack of flatus for at least 24 hours, mesenteric edema, and lack of small bowel feces had an 86% chance of undergoing surgical exploration during their admission. This combination of features also had a positive predictive value of 29% for ischemic small bowel at surgery.