Endothelial expression of tissue factor on saphenous vein and internal mammary artery segments

Abstract

Saphenous vein grafts have significantly higher early and late occlusion rates compared to internal mammary artery grafts. This preliminary study was planned to investigate the pattern of expression of tissue factor (TF), which is the most important initiator of coagulation, in these two widely used grafts. Seven saphenous vein (SV) segments and 5 internal mammary artery (IMA) segments from patients undergoing elective coronary bypass were stained for TF using specific antibodies and immunohistochemistry methods. The results have shown that while IMA segments showed no intimal expression of TF, dilated saphenous vein segments showed significant expression of TF in the intimal layers. Intimal expression of TF in SV grafts could be due to universal preparation techniques which includes surgical extirpation and dilatation or to an inherent difference from the IMA.