Multiple Arterial Injuries and Prolonged Cholesterol Feeding Do Not Increase Percent Lumen Stenosis: Impact of Compensatory Enlargement in the Microswine Model

Abstract

While the swine model is frequently utilized in the study of arterial intervention, it has been difficult to create severe peripheral arterial stenosis without total thrombotic occlusion with a single arterial injury and short-term cholesterol feeding. The combination of multiple arterial injuries and prolonged cholesterol feeding was explored in an effort to create lesions with significant luminal compromise. Nineteen microswine were divided into two groups and fed a high cholesterol diet followed by multiple balloon injuries of the iliac arteries. We conclude that repeated balloon injuries and longer cholesterol feeding significantly increase areas of plaque and necrotic core but do not increase percent stenosis because of arterial compensatory enlargement. The microswine iliac arteries enlarge in relation to plaque area and repeated balloon injuries. The compensatory lumen enlargement may be one of the factors resulting in significant angiographic underestimation of plaque area during the early stage of the atherosclerotic disease, but it may functionally delay important lumen stenosis until the lesion occupies 40% of the internal elastic lamina area. This study suggests that repeated injury and longer cholesterol feeding to increase percent stenosis may not be cost effective in this model. However, this model is good for studying an increase in plaque accumulation.