ABSTRACT
BACKGROUND: The role of damaged endothelium in early graft occlusion has been extensively demonstrated. Seventy percent of early graft occlusions in coronary artery bypass were caused by thrombi overlying areas of endothelial loss. With the increased use of endoscopic vein harvesting, it becomes important to study the extent of endothelial damage by light and electron microscopy. In this study, we compared the degree of endothelial damage inflicted by the open and endoscopic techniques of vein harvesting using light, scanning, and transmission electron microscope. MATERIAL AND METHODS: Ninety samples of saphenous veins from 45 patients prepared for coronary artery bypass grafting (CABG) utilizing both endoscopic and standard open incision techniques were examined using light, scanning, and transmission electron microscopy. These vein samples were prepared in Plasma-lyte solution (Baxter) in combination with or without papaverine, at two distending pressures of 100 or 300 mmHg and at temperatures of either 4 degrees C or 28 degrees C in eight subgroups and one control group. The pathological alterations in the saphenous veins were graded either based on a scoring system (0 = none, 1 = < 10%, 2 = 10-25%, 3 = 25-50%, 4 = > 50%) to assess the degree of damage inflicted by these two different types of saphenectomies or by electron microscopic observed abnormalities, including endothelial cell (EC) separation, EC detachment, basement membrane (BM) exposure, collagen exposure, and EC edema. RESULTS: Using cross-tabulation and Chi-square statistical analysis, we found that the differences in the degree of endothelial damage using either of the techniques is not statistically significant (P > 0.05). CONCLUSION: Our findings indicate that endoscopic and open saphenectomies are technically comparable as far as structural damage is concerned, rendering the endoscopic technique of vein handling the preferred method for CABG.
