Early reactions of the arterial wall, following mechanical trauma. A scanning and transmission electron microscopy study.

Endothelial injury has for a long time been suggested to be an important factor for the development of atherosclerotic lesions. In this study, a superficial, circumferential, injury to the aortic intima was induced via a catheter covered with small stones, introduced into the femoral artery of rabbits. The immediate answer of the arterial wall and the formed elements of the blood was studied with combined scanning and transmission electron microscopy. De-endothelialization was noted and the denuded areas were almost immediately covered by platelets, spreading over the surface and releasing the contents of their granules by time. At some locations deeper injuries to the elastic laminae of the wall could be noted. Especially frequent around these areas, but also common all over the de-endothelialized surface, leukocytes were seen. Both neutrophils, lymphocytes and monocytes could be found. A demarcation of the border of the injury was noted three days after catheterization.