The effects and morphology of atheroembolism in limb arteries: an experimental study

Eroded atheromatous plaques which have released atheromatous material into the circulation are commonly found at autopsy in the abdominal aorta and common iliac arteries in man. In an attempt to study this phenomenon quantitatively, human atheromatous material in suspension was injected intothe femoral and common iliac arteries in rabbits. The weight of atheromatous material injected was varied. There was a critical load for the common iliac artery beyond which there was progressive ascending thrombosis and death of the animal. In rabbits weighing 3 to 5 kg, up to 0.2 g of atheromatous material could be injected intra-arterially with survival of the animal and without producing observable effects. As the amount was increased there was a narrow zone in which survival of the animal with a limp occurred. Beyond 0.2 g, death resulted from ascending thrombosis of the peripheral limb arteries. This eventually reached the bifurcation of the oarta and obstructed the opposite common iliac artery. A thrombus rapidly formed around the atheromatous material. Examination of the atherothrombus by light, transmission electron and scanning electron microscopy showed that it contained cholesterol crystals, lipid material, many platelets, leucocytes and red cells bound together within a fibrin net. The atheromatous material was for the most part in the core of the thrombus.