The Importance of Predicting Bowel Necrosis in Acute Mesenteric Ischemia: Narrative Review

Acute mesenteric ischemia (AMI) is a clinical condition caused by vascular insufficiency, resulting in intestinal damage. Is often underestimated, if not driven by clinical suspicion, due to the non-specific clinical symptoms (usually represented by acute abdominal pain) and the absence of reliable markers, which results in a poor prognosis and high mortality. We can identify three main forms of AMI: arterial, venous, and non-occlusive. Arterial AMI is the most frequent form, caused by occlusion of the superior mesenteric artery or one of its branches. Venous AMI is the least frequent, caused by thrombosis of the superior mesenteric vein or its branches. Non-occlusive AMI is due to a state of hypovolemia, which is frequent in patients who have undergone surgery. Given the difficulty of diagnosis based on the clinic alone, the radiologist plays a central role in identifying radiological signs of intestinal ischemia and in avoiding misdiagnosis. The radiologist's role is mainly to identify factors predictive of necrosis, which allow us to stratify patients and direct them towards the proper management. The aim of this review is to provide indications for an adequate CT protocol, including an unenhanced phase, an arterial phase, and a venous phase, as well as to underline the features to investigate in the different forms of AMI, in order to increase the diagnostic capacity in this challenging disease.