Regional heterogeneity within the aorta: relevance to aneurysm disease.

Vascular remodeling within the aorta results in a loss of structural integrity with consequent aneurysm formation. This degradation is more common in the abdominal aorta but also occurs above the diaphragm in the thoracic aorta. Conventionally, the aorta has been considered a large vascular conduit with uniform cellular and extracellular structure and function. Evidence is accumulating, however, to suggest that variations exist between the thoracic and abdominal aorta, thereby demonstrating regional heterogeneity. Further pathophysiologic studies of aortic dilation in each of these regions have identified disparities in atherosclerotic plaque deposition, vessel mechanics, protease profiles, and cell-signaling pathways. Improved understanding of this spatial heterogeneity might promote evolution in the management of aneurysm disease through computational models of aortic wall stress, imaging of proteolytic activity, targeted pharmacologic treatment, and application of region-specific gene therapy.