Bowel Ischemia Could Be Treated with Balloon Angioplasty

Three experienced radiologists blindly observed contrast-enhanced ischemia-specific computed tomography (CT) images to try and differentiate patients suffering from acute on-chronic mesenteric ischemia (AOCMI) from those with chronic mesenteric ischemia (CMI).

Two observers had substantial agreement that two thirds of AOCMI patients showed ischemia-specific CT findings, including decreased bowel wall enhancement, pneumatosis, or thrombotic SMA clot; the third observer agreed only fairly regarding pneumatosis and thrombosis. All the observers agreed substantially that most patients with AOCMI had unspecific intestinal findings such as mesenteric fat stranding in up to 96%, bowel lumen dilatation in 93%, and bowel wall thickening in 70%, while only few patients with CMI had such findings, probably due to chronic ischemic colitis.

Subsequently, mesenteric revascularization by endovascular therapy was attempted in 50 of the patients, and proved successful in 44 of them. Three of the patients underwent a surgical bypass after failed endovascular therapy. The overall mortality rate was 42%, considered a clear improvement over earlier treatment outcomes. Resection of gangrenous bowel was resorted to only in approximately one third of the patients, and more than half of them avoided surgery altogether. The study was published in the March 2016 issue of Journal of Gastrointestinal Surgery.

“We hope that this study will raise awareness among surgeons and radiologists of the prevalence of AMI in older patients, as well as of the diagnostics-related challenges,” said lead author gastrointestinal surgery specialist Jussi Kärkkäinen, MD, of Kuopio University Hospital. “One third of AOCMI patients presented without any ischemia-specific CT signs; however, any intestinal abnormality in CT together with SMA obstruction should raise suspicion of intestinal ischemia. Furthermore, clinicians need to be aware of the inter-observer variability in the CT interpretation.”

AMI usually results from an occlusion of the SMA, typically caused by arteriosclerosis or embolism; it is usually diagnosed using contrast enhanced CT, but this is often inconclusive, and tends to certainty only after permanent bowel damage has already developed. For the patient's prognosis, it is crucial to make a diagnosis before such bowel damage develops, as AMI usually leads to a life-threatening gangrenous bowel. Previously, the most common course of treatment was resection of the decaying bowel, with an overall mortality rate of over 80%.

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Kuopio University Hospital
University of Eastern Finland