Quantitative Imaging of Transmural Vasa Vasorum Distribution in Aortas of ApoE-/-/LDL-/- double knockout Mice using Nano-CT

Abstract

Ziele: To evaluate the distribution of vasa vasorum (VV) in advanced atherosclerotic lesions (calcified, fibrotic or hemorrhaged) in the aortic wall of apoE-/-/LDL-/- mice in relation to aortic luminal and plaque cross-sectional surface area using high-resolution nano-CT Methode: Aortas from male apoE-/-/LDL-/- mice (n=7) at the age of 80 weeks were infused in situ with contrast agent, harvested for scanning with Nano-CT (NCT) and followed by sectioning for histology. The spatial distribution of Vasa Vasorum [number and surface/cross-section (mm2)] was compared to aortic luminal cross-sectional area in the ascending aorta, aortic arch and descending aorta. Results were complemented with co-localized histology. Ergebnis: The number and cross-sectional area of VV in relation to plaque showed significant differences depending on whether it was a fibrotic, hemorrhaged or calcified plaque (6.8±1.9 vs. 6.9±2.4 vs. 1.4±1.3 respectively, p<0.0001). Plaque area was highest in calcified lesions compared to fibrotic and/or hemorrhaged lesions. The total number and area of VV progressively increased along the aorta from least in the ascending aorta < aortic arch < descending aorta. Plaque type but not plaque cross-sectional surface area correlates to the number and cross-sectional surface area of VV. Schlussfolgerung: Atherosclerotic lesion type but not aortic luminal cross-sectional surface or plaque area is correlated to the number and cross-sectional surface area of VV in different aortic segments in apoE-/-/LDL-/- mice.