Percentage of CABG Procedures Performed Using Internal Mammary Artery Grafts

From Q2 2005 to Q2 2006, internal mammary artery grafts were used, when indicated, in 95% of all CABG procedures performed at Strong Memorial Hospital.

Veins or arteries may be used to bypass obstructed coronary arteries. A piece, or section, of a vein is usually taken from one or both legs. An artery in the chest, the internal mammary artery (IMA), may also be used. A section of other arteries may sometimes be used, such as the radial artery near the wrist.

Use of the IMA to bypass the left anterior descending (LAD) coronary artery (one of the main coronary arteries) has been considered the "gold standard" since 1985 (New England Journal of Medicine, January 2, 1986: 314; 1-6). The National Quality Forum (NQF) includes the use of internal mammary artery grafts as a standard in its National Voluntary Consensus Standards for Hospital Care: An Initial Performance Measure Set, published in 2003.

The routine use of the left internal mammary artery (LIMA) for bypassing the LAD coronary artery with supplemental saphenous vein grafts (taken from a leg vein) to other coronary artery lesions (obstructions) is generally accepted as the standard grafting method (Circulation, August 31, 2004: 110(9); 1168-1176).

More recently, it has been established that the IMA may be safely used in more situations than previously thought, such as during emergency operations, in elderly patients, and in the presence of certain conditions, such as severe left ventricular dysfunction (poor pumping ability of the left ventricle), chronic obstructive pulmonary disease with enlarged lungs, and an obstructed left subclavian artery (located under the collarbone) (Circulation, January 2001: 103(4); 507-512).