Small bowel ischemia caused by strangulation in complicated small bowel obstruction. CT findings in 20 cases with histopathological correlation.

PURPOSE To analyze the CT findings in 20 cases of complicated small bowel obstruction with surgically and histopathologically proven small bowel ischemia, caused by extrinsic venous outflow obstruction of the affected bowel loops and to discuss the question, if bowel wall thickening, abnormal bowel wall enhancement, ascites and mesenteric stranding correlate with the severity of bowel wall damage. METHODS CT scans of 20 patients with surgically an histopathologically proven isolated small bowel ischemia caused by strangulation (10 patients with only partial mural, still potentially reversible small bowel ischemia and 10 patients with transmural irreversible small bowel infarction) were analyzed retrospectively with special emphasis on the presence and degree of small bowel wall thickening, enhancement of the bowel wall, ascites and/or mesenteric stranding at CT and the question whether these findings correlated with the severity of ischemic small bowel wall damage in these patients. RESULTS Small bowel wall thickening, local mesenteric stranding and ascites were equally common in both groups of patients, regardless of whether obstruction and strangulation related small bowel ischemia was transmural or only partial mural. Out of those patients who were examined by contrast enhanced studies no patient showed lack of enhancement along the ischemic bowel loops. CONCLUSION Although highly sensitive and specific for small bowel ischemia in complicated small bowel obstruction, the presence and degree of bowel wall thickening, ascites or local mesenteric stranding at CT do not correlate with the severity of ischemic small bowel wall damage and even the presence of bowel wall enhancement does not exclude severe and potentially transmural bowel infarction in these patients.