Observation of atherosclerotic lesions by an intravascular microscope in patients with arteriosclerosis obliterans

The magnification power of conventional fiberscopes for intravascular use is up to ×30, and therefore they are not feasible for observation of fine structures of vascular changes. We devised a microscope that enables percutaneous transluminal observation of the vascular luminal changes of cellular order. Thus we examined its feasibility in patients. The microscope was 8F in diameter with a rod lens inside, and its magnification power was from ×150 to ×350. The microscope was introduced into the iliac or femoral artery for observation of vascular lesions during angioplasty in seven patients with arteriosclerosis obliterans. With the aid of vital staining individually damaged endothelial cells, fibrin threads, foam cells, collagen, elastic fibers, and structure of microthrombi were discriminated clearly. The results indicate that structures of human vascular lesions of cellular order can be observed percutaneously by the intravascular microscope.