Glucose Metabolism in the Vessel Wall Correlates With Mechanical Instability and Inflammatory Changes in a Patient With a Growing Aneurysm of the Abdominal Aorta

Abstract

It has been shown by our group and by others1,2 that increased glucose metabolism in the aortic wall of patients with aneurysms of the abdominal aorta (AAA) can be visualized in vivo by 18F-fluorodeoxyglucose positron emission tomography (FDG-PET). Interestingly, an increased glucose metabolism in AAA wall was strongly associated with rapid progression or acute symptoms and therefore increased rupture risk. Moreover, the PET signal was correlated with histopathological changes such as activation of MMP-9, collagen, and elastic fibers as well as macrophage infiltration in the AAA wall. (It is well documented by preclinical studies that increased activity of MMP9 facilitates aneurysm rupture). However, the true prognostic value of increased FDG uptake for AAA progression and rupture risk still remains uncertain. To provide clear evidence, surveillance of small AAA by multiple PET scans would be necessary over a long period. However, PET studies are not routinely performed in patients with AAA for practical and ethical reasons and therefore an increase in glucose metabolism in AAA wall was not directly observed until now. Further, it is …