[Small bowel obstruction from adhesions: which CT severity criteria to research?]

To determine the value of known computed tomographic (CT) criteria to differentiate non-complicated from complicated (strangulation, necrosis) small bowel obstruction.

43 patients with a definitive diagnosis of small bowel obstruction based on clinical, sonographic, CT, surgical and pathological findings were included. All patients had small bowel obstruction caused by adhesions confirmed at surgery. The obstruction was non-complicated in 28 patients and complicated in 15 patients. The CT examinations from all patients were retrospectively reviewed by three experienced radiologists using a set of pre-defined criteria. Attention was focused on the following signs: reduced enhancement of the small bowel wall, mural thickening, congestion of small mesenteric veins, and ascites. Results were correlated with surgical and/or pathological data.

For the diagnosis of complicated obstruction, reduced bowel wall enhancement had a sensitivity of 57% and a specificity of 100%, a bowel wall thickness greater than 3 mm had a sensitivity of 35% and a specificity of 100% and a bowel wall thickness less than 1 mm had a sensitivity of 35% and a specificity of 93%. Ascites and congestion of small mesenteric veins were not significant. The multivariate analysis showed that the association of bowel-wall thickening and reduced enhancement of the small bowel wall was significant (sensitivity of 71%, specificity 100%, and accuracy 90%).

Among the CT criteria used to diagnose complications from small-bowel obstruction that were evaluated in this study, only three were significant with a high specificity but low sensitivity.