A comparative study of endothelial cell injury during open and endoscopic saphenectomy: An electron microscopic evaluation

Background: The role of damaged endothelium in early graft occlusion has be en extensively demonstrated. Seventy percent of early graft occlusions in c oronary artery bypass were caused by thrombi overlying areas of endothelial loss. With the increased use of endoscopic vein harvesting, it becomes imp ortant to study the extent of endothelial damage by light and electron micr oscopy. In this study, we compared the degree of endothelial damage inflict ed by the open and endoscopic techniques of vein harvesting using light, sc anning, and transmission electron microscope. Material and Methods: Ninety samples of saphenous veins from 45 patients pr epared 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 300mmHg and at temperatures of either 4 degreesC or 28 degreesC in eight subgroups and one control group. The path ological alterations in the saphenous veins were graded either based on a s coring system (0 = none, 1 = < 10%, 2 = 10-25%, 3 = 25-50%, 4 = > 50%) to a ssess the degree of damage inflicted by these two different types of saphen ectomies or by electron microscopic observed abnormalities, including endot helial cell (EC) separation, EC detachment, basement membrane (BM) exposure , collagen exposure, and EC edema. Results: Using cross-tabulation and Chi-square statistical analysis, we fou nd 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 a re technically comparable as far as structural damage is concerned, renderi ng the endoscopic technique of vein handling the preferred method for CABG.