'Hemorrhagic' and microvascular phenomena within the arterial wall.

OBJECTIVE To study microvasculature and hemorrhage within the arterial wall. DESIGN Human autopsy specimens of the arch of the aorta, the carotid, brachiocephalic, subclavian and coronary arteries perfused with liquid casting material and maintained at physiological pressure until the material had set. MAIN RESULTS Evidence of dense microvasculature and other phenomena which have the morphological appearance of 'hemorrhage' within the arterial wall, coupled with calcified matter and other impressions made on the cast by atherosclerotic plaques. CONCLUSIONS The findings lend support to suggestions in the literature that neovascularization may play a role in the pathogenesis of coronary atherosclerosis and its sequelae, that hemorrhage into the intima may be due to rupture of capillaries which are derived from the coronary lumen, and that an increase in microvasculature occurs in the immediate vicinity of localized atherosclerotic lesions.