[Immunocytochemical and ultrastructural study of saphenous vein, internal thoracic artery, and right gastroepiploic artery in coronary artery bypass grafting].

The arterial conduits such as internal thoracic artery (ITA) and right gastroepiploic artery (GEA) are widely used in coronary artery bypass surgery because of their resistance to atherosclerosis. In this study, immunophenotypes of smooth muscle cells (SMCs) in intima and media of ITA, GEA and saphenous vein (SV) were studied using monoclonal antibodies specific to cytoskeletal proteins; actin (A), vimentin (V) and desmin (V). In addition, the ultrastructures of endothelium of these vessels were examined. The most SMCs in intima and media of ITA and GEA were found positive for (A) and (V) but negative for (D). In contrast, the majority of SMCs both in intima and media of SV were found positive for (A), (V) and (D). The ultrastructure of endothelium of ITA and GEA showed the deeper penetration of cytoplasmic process than SV, which might anchor the endothelium. We suggest the morphological difference of endothelium and phenotypic diversity of SMCs between arterial and venous grafts may account for the different susceptibility to atherosclerotic changes in coronary bypass grafting.