Coronary artery bypass surgery
A coronary artery bypass graft (CABG) or heart bypass is a surgical procedure performed in patients with coronary artery disease for the relief of angina and possible improved heart muscle function. Veins or arteries from elsewhere in the patient's body are grafted from the aorta to the coronary arteries, bypassing coronary artery narrowings caused by
atherosclerosis and improving the blood supply to the myocardium (heart muscle).
First, the sternum is cut down the middle with a special bone saw and the chest opened (a procedure known as "cracking the chest" or a median sternotomy). Depending on a number of factors, the surgeon may decide to place the patient on cardiopulmonary bypass ("on-pump") or use suction-stabilizing devices to hold the heart still while sewing the anastamoses ("off-pump"). Blood vessels are harvested from elsewhere in the body for grafting. Sometimes artery end branches supplying tissues near the heart are rerouted to create the bypass.
Typically, the saphenous vein from the leg and the left internal mammary artery (LIMA) are used for the bypass. Veins used either have their valves removed or are turned around so that the valves in them do not occlude blood flow in the graft. LIMA grafts are longer-lasting than vein grafts, both because the artery is more robust than a vein and because, being already connected to the aorta, the LIMA need only be grafted at one end. For this reason, the LIMA is usually grafted to the left anterior descending artery (LAD), which supplies the left ventricle, the part of the heart that pumps oxygenated blood around the body. Alternatively, an artery such as the radial artery from the arm, may be used in place of a vein. This is believed to prolong the life of the grafts but this has yet to be proven.
Based on the extent of blockage in your coronary arteries, surgical treatment may be the best alternative. Bypass surgery creates new pathways of circulation around existing blockages or narrowings, allowing blood to reach your heart muscle again. In most cases, a healthy blood vessel from another part of your body (most commonly the saphenous vein in the leg, the internal mammary artery in the chest, and sometimes the radial artery in the arm) is used. This vessel becomes a "conduit" to the coronary artery at a point beyond the narrowed artery. The blocked or narrowed portion of the artery is "bypassed" with this vessel, allowing blood to flow to the heart muscle again.
Depending on the individual patient's condition, extent of coronary artery disease and coronary anatomy, one of four approaches will be chosen to perform the coronary artery bypass surgery. The operative approach is planned prior to surgery to meet the needs of each individual patient. Two of these approaches use traditional techniques and two use minimally invasive techniques.
The traditional or standard approach involves having a maximal incision that is called a median sternotomy, a midline chest incision over the length of the sternum (breastbone). The patient is placed on the heart-lung machine while creating the bypass grafts on the heart. The traditional or standard approach using "heart stabilizers" involves a median sternotomy incision. With this technique, the Inova cardiac surgeon uses heart stabilization techniques while creating the bypass grafts on a beating heart. The heart-lung machine is not used during this approach.
The minimally invasive approach using the heart-lung machine involves having a small incision on the chest wall to accommodate special instruments. The heart-lung machine is used while creating the bypass grafts on the heart. The minimally invasive approach using "heart stabilizers" involves a small incision on the chest wall and stabilization techniques while creating the bypass grafts on a beating heart. The heart-lung machine is not used during this approach.