A comprehensive approach to visual and functional assessment of experimental vascular lesions in vivo

The rat carotid injury model is the most widely used model to study the pathophysiology of neointimal hyperplasia as well as the value of novel therapeutic approaches to limit vasoproliferative diseases such as restenosis. For lesion assessment, the current gold standard of histomorphometry neither provides integral insight into the vascular lesion in vivo nor assesses of functional lesion-associated flow alterations and the time course of lesion development. To overcome these limitations, we applied and validated duplex sonography as a novel tool for comprehensive lesions assessment in vivo. Left rat common carotid arteries (CCA) were balloon injured. Duplex sonography was performed in both injured and noninjured CCAs before and up to 14 days postinjury. Sham-operated animals served as controls. The parameters determined were vessel lumen diameter as well as systolic and end-diastolic flow velocity, time-dependent lesion development, and intra- and interobserver variability. Subsequently, the model was applied to validate the therapeutic effect of gene transfer into the vessel wall and compared with histomorphometry. We show that duplex sonography in the experimental carotid injury model allows accurate follow-up of lesion development in vivo with low intra- and interobserver variability. It can be easily adopted to assess the efficacy of therapeutic approaches even with limited technical experience and adds valuable functional data to mere postmortem histomorphometric analysis, thereby closing the gap between experimental approaches and clinical importance of vascular lesions.