Revascularization of the heart; histologic changes after arterialization of the coronary sinus.

A free graft of vein was placed between the aorta and coronary sinus. Three weeks later the sinus was partially occluded at its ostium in the right auricle. Blood from the aorta was made available to the myocardium by way of the venous system. After these procedures were done a histologic study of the venous and arterial channels was carried out. The coronary sinus and its tributaries showed hyperplasia of the intima. The anterior cardiac veins showed dilatation with little or no hyperplasia of intima. None of the veins became occluded. Complete occlusion of major coronary arteries was done. These arteries distal to the occlusion showed medial sclerosis and atrophy. They did not show thrombosis. The myocardium distal to an occluded artery showed many vascular channels. A N OPERATION was developed in this laboratory which made an additional source of aortic blood available to the myocardium.1 This operation is described on page 801, in this issue. It was shown by experiment that this operation protected the heart against occlusion of a major coronary artery. In view of the fact that this operation appeared to have therapeutic possibilities for patients with coronary artery disease, this study on the anatomy of the vascular system was carried out. The specimens used in this study were those upon which Hahn and Beck carried out multiple ligation of major coronary arteries.3 METHOD OF STUDY This report was based upon a study of 37 specimens. A variety of procedures was carried out on the dogs from which these specimens were obtained. The two stage operation was done with an interval of three weeks between the placing of the graft and the partial occlusion of the sinus at its ostium in the right auricle. One or more major coronary arteries were ligated subsequently. Figure 1 shows the various areas from which sections were made. The sections were stained by hematoxylin and eosin and also by the trichrome and van Gieson-Weigert method. The following protocol illustrates the se-From the laboratory of Dr. quence of events in producing one of the specimens for study. (1) A free vein graft was introduced between aorta and coronary sinus; (2) three weeks later the coronary sinus was occluded at its ostium to a diameter of 3 mm.; (3) coronary arteries were ligated at intervals of three weeks to include (a) complete ligation of descending ramus and septal artery, (b) complete ligation of …