Relationship between plaque mass and neointimal hyperplasia after stent placement in Yucatan micropigs.

Abstract

To determine whether the amount of neointima found after stent placement is related to the preexistent plaque mass in the peripheral arteries in micropigs. Twenty-six peripheral arteries were studied in 14 Yucatan micropigs in a denudation and diet-induced atherosclerosis model. Quantitative angiographic and intravascular ultrasound (US) analysis were performed before and after stent placement and at follow-up 6 weeks after stent placement. At follow-up, the peripheral arterial tree was fixed by means of pressure perfusion, processed for histologic analysis, and analyzed morphometrically with a computer-based system. Preexistent plaque correlated strongly with intimal hyperplasia measured on US images (r = .81, P < .001) or in histologic sections (r = .53, P = .006). No correlation was found between dilation ratio and intimal hyperplasia or between balloon-to-lesion ratio and intimal hyperplasia. In multivariate models of intimal hyperplasia, preexistent plaque and early gain in lumen diameter depicted at angiography were independent explanatory variables. The amount of plaque present before stent placement was a determinant of the amount of intimal hyperplasia present after stent placement.