Vascular injury and thrombosis: A scanning electron microscopic study

Injury to the blood vessel wall and atherosclerosis enhance the possibility of thrombus depostion. A knowledge of the changes in vascular morphology and the extent of thrombus deposition produced by injury is essential in elucidating the mechanism of this reaction. In the present work, scanning electron microscopic technique was used to examine the canine blood vessel wall at or near a site of injury caused by vascular clamping. Proximal to the clamping, the endothelial folds in normal vessels are clearly visible. The intima is completely severed at the site of clamping. At a distance of 1mm distal to the injury, the vascular wall is completely covered with a layer of thrombi, composed mainly of platelets, fibrin and trapped erythrocytes. Thus, injury to the blood vessel wall destroys the endothelial structure and triggers thrombus deposition.