The Patient Underwent Bypass Surgery for Life-Threatening Coronary Artery Disease

The patient underwent bypass surgery for life-threatening coronary artery disease. With the aid of extracorporeal circulation, the right internal mammary artery was taken down to the left anterior descending artery and saphenous vein grafts were brought from the aorta to the diagonal, the right coronary artery, and the posterior descending artery. What is the correct ICD-9-CM coding for this procedure?

A) single internal mammary artery bypass; aortocoronary artery bypass of three vessels
B) aortocoronary bypass of three coronary arteries
C) aortocoronary bypass of four coronary arteries
D) single internal mammary artery bypass; aortocoronary bypass of three vessels, extracorporeal circulation