The destructive effects of sclerosant ethanolamine oleate on mammalian vessel endothelium.

Ethanolamine oleate (EO) used widely in sclerotherapy against esophageal varices was studied for its pharmacological effect on blood coagulation and vascular damage in animals. Blood coagulation was completely inhibited by EO at a concentration of 0.31%. EO destroyed the endothelial cells of the vessel of dog and rat within one minute after injection into the vessels. An accumulation of fibrin and platelets on the surface of the damaged vessel was observed electron microscopically. Mural thrombus was formed in a few hours and the thrombus occluded the blood stream in the vein. From these animal experiment, intravasal injection of EO was considered to cause the disappearance of varices by the following two processes: collapse of varices because of occlusion of the blood stream and shrinking of the obstructed thrombus through organization.