Assessment of inflammatory infiltration and angiogenesis in the thrombus and the wall of abdominal aortic aneurysms on the basis of histological parameters and computed tomography angiography study

The proliferation of vessels within the aneurysm’s wall and the intraluminal thrombus of abdominalaortic aneurysm (AAA) may be the main factor responsible for progression and rupture of AAA. The aim of thisstudy was to compare the parameters of the thrombus (size, density, contrast enhancement) measured by computedtomography (CT) with histological assessment of thrombi removed during surgery. 29 patients with AAAwere examined with angio-CT. Post-surgery histopathological evaluation of AAA was performed. Slides werestained with markers of B- (CD20) and T-lymphocytes (CD3), and markers of endothelial cells (CD34). Thrombiwere enhanced after contrast media administration in angio-CT (p = 0.002). There was a statistically significantcorrelation between contrast enhancement and the presence of B lymphocytes. Intensity of endothelial cellmarker expression significantly correlated with the presence of inflammatory T- and B-cells. No statistical significantcorrelation was found between contrast enhancement of the thrombus and markers of endothelial cells.The accumulation of inflammatory cells in the wall of AAA thrombus results in the formation of new vesselswhich participates to the instability of the thrombus and AAA wall. Assessment of the inflammation and neovascularizationin the wall and thrombus of the AAA might be an important factor in monitoring the progressionand the risk of aneurysm’s rupture