Calcification and proteoglycan accumulation following balloon angioplasty and stenting

To examine in a porcine model if a correlation exists between calcification and the hyperplastic response of arteries to balloon angioplasty and stenting.

Eleven Sinclair miniature swine on an atherogenic diet underwent balloon angioplasty or endovascular stenting in nondiseased external iliac arteries using standard procedures. Ninety days postoperatively, the animals were euthanized, and histological sections of the dilated, stented, and control arteries were examined for evidence of calcification and increased proteoglycan accumulation.

An increase in proteoglycan accumulation and the loss of integrity of the internal elastic lamina were observed in both the dilated and stented arteries. Diffuse calcification was seen in the media/neomedia of both groups, and large calcium salt deposits were observed in the dilated arteries at the site of the internal elastic lamina and near the stent struts in stented arteries.

Internal elastic lamina loss of integrity appears to be related to an increase in proteoglycans through the formation of a neointima, and the arterial hyperplastic response to balloon angioplasty and stenting seems to lead to calcification.