The rate of growth of interarterial anastomoses in chronic coronary artery occlusion

Abstract

The transformation of a small myocardial arteriole into a functionally efficient intercoronary anastomotic artery was studied in the dog heart after slowly occurring occlusion of the circumflex branch of the left coronary artery. Growth of collateral vessels was efficient and prevented myocardial infarction in 50% of the animals. A two-phase transformation process of the vessel wall is described on the basis of quantitative data which deal with the increase in the vascular radius, with the increase in the volume of the tunica media and with the rate of growth of the vessel. The frequent observation of smooth muscle cell mitosis in the vessel wall suggests that smooth muscle cell hyperplasia caused the increase in vessel wall volume.