Extracardiac anastomosis in coronary ostial occlusion.

In his review of the physiology of the coronary circulation, Wiggers (1936) enumerated three types of compensatory anastomosis that may develop after coronary occlusion: (1) through development ofnew ititercoronary communications, (2) through formation of extracardiac communications, and (3) through enlargement of arterio-luminal channels. Widespread minor anastomoses are known to exist between branches of the coronary arteries and branches of extracardiac arteries around the major vessels at the root of the heart, and it is believed (Hudson, Moritz, and Wearn, 1932) that this potential extracardiac coronary collateral circulation may be of significance in compensating for sclerosis of the large trunks of the coronary arteries. It is not generally appreciated, however, that such extracardiac collateral arteries may attain a considerable calibre, as in the case reported here.