Vascular trauma induced by clamping- correlation between surface ultrastructure and fibrinolytic activity.

The effects of application of a vascular clamp for 30 sec were studied on the femoral vessels in rats. Control and injured vessel segments were studied with scanning electron microscopy and with a histochemical method to estimate the fibrinolytic activity in the vessel walls. Endothelial injury with loss of endothelial cells was induced by application of the clamp. This was correlated to a reduction of the fibrinolytic activity in the vessel wall. In arteries re-endothelialization was seen three weeks after induction of the trauma, and it was completed after eight weeks. Venous lesions healed earlier. The re-endothelialization was followed by a return to normal fibrinolytic activity.