Acute Superior Mesenteric Arterial Occlusion Caused by a Thoracic Aortic Mural Thrombus in a Patient without Coagulation Disorder or Aortic Disease: A Case Report

Introduction: Aortic mural thrombus (AMT) formation in a patient without hypercoagulability and preexisting aortic disease is very rare, and acute superior mesenteric artery (SMA) occlusion resulting from AMT is clinically infrequent. Case presentation: A 70-year-old woman was transferred to our institute with a diagnosis of acute SMA occlusion. Contrast-enhanced computed tomography (CECT) revealed thromboemboli in the SMA and a thoracic AMT. She immediately underwent angiography and subsequent endovascular aspiration and transcatheter infusion, which recanalized the SMA. However, CECT suggested intestinal ischemia; therefore, she underwent intestinal resection, and we administered anticoagulant therapy with heparin and warfarin postoperatively for the thoracic AMT. Although repeat thrombus formation developed in an ileal branch despite anticoagulant therapy, she had no abdominal symptoms; therefore, we continued the anticoagulant therapy. CECT 3 months later confirmed the absence of thoracic AMT and normal ileal findings. Conclusion: We report a case of acute SMA occlusion and preceding splenic infarction that resulted from thoracic AMT in a patient without hypercoagulability and preexisting aortic disease. AMT should always be considered as a cause of acute SMA occlusion in patients without heart disease, including atrial fibrillation or severe arteriosclerosis.