Not most common
The internal mammary artery is the best graft
for coronary artery bypass grafting (cabg), saphenous vein used for backup.
One of the best operations ever invented, the left internal mammary artery to coronary artery bypass graft is the gold standard by which almost any vascular operation is compared to with a patency of over 90% at 10 years. There is almost no operation with a patency that high.