Borderline Mesenteric Ischemia Caused by Acute Aortic Dissection Borderline Mesenteric Ischemia in Aortic Dissection

To make a diagnosis of mesenteric ischemia in acute aortic dissection, we have examined superior mesenteric artery (SMA) with transesophageal echocardiography (TEE) in addition to CT scan, and experienced borderline mesenteric ischemia, which is to be presented. The SMA was visualized with TEE by advancing the probe into the stomach and directing the transducer posteriorly. The TEE findings of SMA was correlated to the clinical course and CT findings in 28 cases with aortic dissection that extended to the abdominal aorta. Borderline mesenteric ischemia was found in four patients (14.3%). Preoperative CT showed patent and opaque SMA. However, TEE revealed narrowed true lumen in the proximal SMA or obstructed orifice of SMA by intimal flap. Two patients developed bowel necrosis and died. One patient underwent revascularization surgery. In another patient, obstruction of SMA orifice by intimal flap was released within 24 hours by spontaneous tear of flap and subsequent depressurization of false lumen. This patient had mild bloody stool and transient septic shock but they improved. There are cases with borderline mesenteric ischemia as well as those with totally necrotic intestine. TEE may provide additional information for assessing mesenteric ischemia in acute aortic dissection.