Acute bowel ischemia: analysis of diagnostic error by overlooked findings at MDCT angiography

Abstract

To retrospectively evaluate the frequency and type of findings that were missed in the original reports of multi-detector CT angiography (MDCTA) in patients with suspected acute bowel ischemia. From January 2007 to March 2011, a series of 35 patients who underwent MDCTA of the abdomen and pelvis and had surgery were included. The reports of the initial CT were retrospectively compared with the discharge diagnosis and surgical reports. Discrepant or missing findings were re-evaluated and divided into relevant or not relevant regarding the diagnosis. In 23 of the 35 patients (66 %), all findings were correctly diagnosed in the initial MDCTA report. In the remaining 12 of the 35 patients (34 %), lesions that were not reported were present at surgery. In 10 of the 12 (83 %) patients, the overlooked findings were relevant and subtle: gas in the portal vein (n = 3), gas in the bowel wall (n = 3), gas in the portal vein and bowel wall (n = 2), thrombotic occlusion of the superior mesenteric artery (n = 1), and thrombotic occlusion of the inferior mesenteric artery (n = 1). In 2 of the 12 (17 %) patients in whom the MDCTA-overlooked findings were classified as non-relevant, bowel ischemia was found at surgery. With retrospective image interpretation, 83 % of the patients with occlusive mesenteric ischemia at surgery were correctly identified, whereas the remaining 17 % with non-occlusive mesenteric ischemia at surgery showed non-relevant findings at MDCTA. About 33 % of relevant findings of bowel ischemia were overlooked by the initial MDCTA interpretation, most were subtle findings. However, secondary reading revealed most of these findings and can serve to improve diagnostic performance.

Detecting acute mesenteric ischemia in CT of the acute abdomen is dependent on clinical suspicion: Review of 95 consecutive patients

“…All findings of AMI were correctly stated without any shortcomings in 67% of the initial CT reports. Similar results have been reported previously in studies with smaller study populations [19,22]; the latter study included 35 patients imaged solely with a biphasic CT protocol. Based on the essentially correct initial CT reports with minor shortcomings in the current study, it appears that it was easier for the radiologists to detect and interpret vascular findings than the more subtle intestinal findings.…”

Diagnostic conundrum: simultaneous gallstone ileus and a gas-filled inguinal hernia in a patient with lower abdominal pain

“…However, the gas initially appeared extraluminal, and so although a more benign cause was a possibility ischaemic small bowel and/or perforation needed to be excluded. Both of these are serious conditions that require immediate surgical management 2. Fortunately, in this case the patient required surgical intervention anyway for the gallstone ileus, and so his management would not have changed had the small bowel diverticulosis been identified correctly on CT.…”

“…The small bowel within the hernia was thin-walled and of normal calibre, and the wall showed normal enhancement. The distribution of gas along the mesentery was not typical for perforation, and there were no other features of bowel ischaemia (bowel wall thickening, bowel distension, altered bowel wall perfusion) 2. However, these features can be variable in the setting of ischaemia; and although there are benign causes for extraluminal gas both vascular compromise and perforation of the bowel loop within the hernia needed to be considered as they are life-threatening pathologies 3…”

Intestinal fatty acid binding protein (I-FABP) as a marker for acute intestinal ischemia

“…Firetto MC et al, did a retrospective analysis of findings that were absent in the original reports of multi-detector CT angiography (MDCTA) in patients with suspected acute bowel ischemia. 15 Most of the subtle findings that were overlooked by the initial MDCTA interpretations account for about 33% of the relevant findings of bowel ischemia.…”