Endothelial Injury During the Preparation of the Saphenous Vein for Use as Coronary Bypass Graft: A Light and Electron Microscopic Study

In order to determine and discuss the optimal preparation technique to use the human saphenous vein as a graft, the effects of solution and pressure variabtes on vein morphology was compared by scanning electron and light microscopy. Saphenous vein speciemens obtained from 10 patients who will undergo coronary artery bypass graft operation were divided into 7 segments, each one 3-4 cms long and 7 groups are formed. Group 1 was taken as control. In groups 2 and 3 salineheparİn solution, in groups 4 and 5 blood-heparin solution and in groups 6 and 7 blood-salineheparin solution were applied at 28°C, under 100 mmHg and 300 mmHg pressure producing a distention in the veins and the segments were kept in the related solutions for one hour. Then, each segment was divided into two pieces. First pieces were examined under a routine light microscope in % 10 buffered formalin solution and the second examination was performed after staining with Hematoxylin-Eosin and Elastic Van Gieson (Verhoeff). The second pieces were perfused with cold buffered (pH 7 .2) % 3 gluteraldehyde under 100 mmHg which is equivalent to in vivo arteria1 pressure. Following routine electron microscopic examination and - evaluation with scanning electron microscope (SEM) was made. In the examination performed with light microscopy and SEM, pathological damage was evaluated as endothelial cell separation, endothelial cell loss, exposure of the hasement membrane; intimal and medial edema. These pathological damages were scored between O and 4. Median scores were calculated for each group. The median scores were as follows: 0.6 ± 0.5 in Group 1 (control), 6.6 ± 0.5 in Group 2 (saline-heparin-1 00 mmHg-28°C), 17 ± 0.7 in Group 3 (saline-heparin-300 mmHg-28°C), 5.6 ± 0.5 in Group 4 (blood-heparin-100 mmHg- 280C), 12 ± 0.7 in Group 5 (blood-heparin 300 mmHg-28°C), 7.6 ± in Group 6 (blood-salineheparin- 100 mmHg-28°C), 17.5 ± 1.3 in Group 7 (blood-saline-heparin-300 mmHg-28°C). The scores in Group 4 was interpreted as the closest ones to the control group compared to the scores of other groups. Although local endothelial loss and separation was observed in Group 4, the score of this group was found to be statistically significant compared to Group 5 (p<0.02), Group 3 (pKeywords: Coronary bypass surgery, endothelial damage, saphenous vein