Methods: Fifteen 3-4 month old Wistar Albino type female rats weighted 300-400 g were anesthetized and the abdominal aorta was explored with median laparotomy. Distal segment of the abdominal aorta was clamped with a microvascular clamp. After almost 10 minutes, occluded segment with microvascular clamp was excised and defined as the clamp group. The incision lengthened proximally and thoracic aorta was explored. The samples of the thoracic aorta segment were defined as the control group. These two sampling groups were prepared for scanning electron microscopy. The analysis is performed by a single blind method and results were analyzed statistically.

Results: No endothelial damage was observed in the samples of the control group. In microvascular clamp group, there was type 1 damage in 10 samples (66.7%), type 2 damage in four samples (26.6%) and type 3 damage in one sample (6.6%). The difference between microvascular clamp and control group was statistically significant in terms of endothelial damage (p<0.001).

Conclusion: Vascular occlusion using with microvascular clamping causes vascular endothelial damage. We believe that type 2 or type 3 endothelial damage can cause early or late thrombosis and/or restenosis due to permanent damage of the endothelial surface.