Will the real plaque vasculature please stand up? Why we need to distinguish the vasa plaquorum from the vasa vasorum

Abstract

Many studies of experimental atherosclerosis and pathologic observations of human specimens have provided evidence supporting a correlation between vascularization of the atherosclerotic plaque and its natural growth and progression toward acute failure, associated with clinical events. The growing interest in the topic is illustrated by several excellent recent reviews discussing the molecular mechanisms that might play a role in the formation of plaque vasculature and that could explain some of the observed associations with pathologic features of experimental and human atherosclerotic lesions. At the same time, these reviews also emphasize that the field is still largely in uncharted territory. Hoping to spark some new investigations, we are taking this opportunity to question some of the common assumptions and to highlight less explored mechanisms. Finally, we are proposing to adopt the term vasa plaquorum to refer to the neovasculature located within the atherosclerotic plaque to distinguish it clearly from vasa vasorum, the native, supporting vasculature of the artery. We suggest that this new nomenclature offers a potential solution to eliminate ambiguity regarding implicit, but frequently neglected, differences between these structures. We think these points are relevant for future efforts to tailor diagnostic tools and therapeutic interventions targeting plaque neovascularization for the clinical management of atherosclerosis.

Figure 1.

Three-dimensional confocal reconstruction of the neovasculature of an experimental lesion in the carotid artery of the p22phox transgenic mouse (fluorescence microangiography).

Figure 2.

Human atherosclerotic plaque with evidence of vasa vasorum sprouting (inset) into the plaque (Movat pentachrome staining).

Figure 3.

Neovessels in atherosclerotic plaque in the mouse carotid artery ligation model demonstrated by CD31 staining for endothelial cells. Red = CD31, green = elastin (autofluorescence), blue = nuclei. Scale bar = 100 micrometers.