Effect of bilateral internal mammary artery ligation on coronary circulation in dogs.

BILATERAL ligation of the internal mammary arteries was proposed by Fieschi as a simple surgical means of treating patients with coronary artery disease. The procedure aims to increase the blood pressure in the pericardiophrenic branches of the internal mammary arteries and, thereby enhancing coronary anastomoses to the myocardium. Observations made on patients have been conflicting,' as have the data based on animal experiments.' ' 4 These experiments were therefore designed to test whether bilateral internal mammary ligation actually improves the collateral arterial blood supply to the myocardium of the dog subsequent to surgical narrowing of a coronary artery and to assess the effect of internal mammary artery occlusion on central internal mammary arterial pressure.