Background and Aims: The aim of the study was to conduct morphological and immunomorphological characterization of thoracic aortic aneurysms. The obtained data allowed us to predict the presence of a clinical picture of aortic dissection with high probability. Methods: The material for the study was the segments of the wall of the aortic aneurysm obtained during the operation of prosthetics of the thoracic aortic aneurysm. Men among the patients were 35 people, women - 8. The patients ranged in age 33 to 69 years. Monoclonal antibodies to monocytes and macrophages (CD68), T cells (CD3, CD4, CD8), antibodies to Willebrand factor, NO-endothelial synthase and smooth muscle cell actin were used for immunomorphological study. Results: Counting the amount of vasa vasorum in the adventitia of an aortic aneurysm revealed a statistically significant difference between the amount of vasa vasorum in the group of patients with an active inflammatory reaction compared to patients with a moderate inflammatory reaction in the aortic wall without an inflammatory process. Heterogeneity of vasa vasorum endothelium was revealed in the immune response to NO-synthase. Endothelial cells in vasa vasorum could not give a positive reaction with antibodies to NO-synthase, nearby Vasa vasorum vessels contained stained endothelial cells. Conclusions: Some of the cytokines expressed by T cells and macrophages, in addition to enhancing inflammation, also contribute to angiogenesis. This is obviously due to an increase vasa vasorum in tunica media and tunica adventitia samples with abundant inflammatory infiltrates. Aortic dissection is a complication of macrophage inflammation.
