Experimental Prevention of Myocardial Infarction by Bronchial Collateral Circulation

Myocardial infarction in dogs, resulting from gradual total occlusion of the left circumflex coronary artery by an ameroid constricting ring, was prevented by lingular cardiopneumonopexy (after ligation of the lingular branch of the left pulmonary artery). Ventriculography demonstrated adequate contractility of the left ventricle, and selective intercostobronchial angiography in vivo revealed abundant bronchomediastinal-coronary collateral circulation as early as three weeks postoperatively. Corrosion casts of hearts following selective injection of the bronchial arteries demonstrated bronchomediastinal collaterals and their anastomosis with the coronary arteries. Serial histologic sections of myocardium and attached pulmonary tissue revealed blood vessels (arterioles measuring 100μ or more in external diameter) directly connecting lung tissue to epicardium. All control animals in which an ameroid ring was applied but lingular cardiopneumonopexy was not performed suffered large posterobasal myocardial infarcts.