Microscopic evaluation of an occluded intracoronary Palmaz-Schatz stent removed before coronary artery bypass grafting.

Intracoronary implantation of stent devices is a new interventional technique with a promising role in the treatment of acute coronary occlusions caused by intimal dissection and suboptimal results of percutaneous transluminal coronary angioplasty. However, the prolonged presence of stent material embedded in the arterial wall may generate unknown late consequences. Major complications consist of subacute to chronic occlusion and restenosis. To elucidate the underlying cause we removed an angiographically occluded intracoronary artery Palmaz-Schatz stent before coronary artery bypass grafting. Scanning electron microscopy showed thorough coating of the metal struts of the stent by normal neoendothelial cells. Side branches arising at the level of the stent were patent. According the specific angiographic feature thrombotic occlusion originated distally of the stent.