Surgical Procedures for Heart Disease Atherosclerosis and the resulting coronary artery disease are progressive. This means that once these problems develop, they will continue to worsen until they are successfully treated. When lifestyle changes or medication cannot control the progression of the disease, surgery may be necessary. Possible procedures performed to treat this condition include coronary artery bypass surgery, coronary angioplasty, and placement of a stent.
Coronary artery bypass surgery, commonly called bypass surgery, is highly effective for people who have angina and whose coronary artery disease is not widespread. Bypass surgery is the procedure most widely used to treat coronary artery disease due to atherosclerosis. It can improve exercise tolerance, reduce symptoms, and decrease the amount of medication needed. Bypass surgery is most likely to beneﬁt people who have severe angina that cannot be controlled with medication, a normally functioning heart, and no previous heart attacks. About 85 percent of patients who undergo bypass surgery experience complete or signiﬁcant relief of symptoms.
The procedure involves grafting (transplanting healthy tissue from one part of the body to another) veins or arteries onto the coronary artery to receive blood ﬂow, thereby “bypassing” the obstructed area. Usually the bypass veins are taken from the leg. Most surgeons also use at least one artery as a graft. The bypass artery usually is taken from beneath the chest wall. These arteries rarely develop atherosclerosis, and more than 90 percent of them remain open and work prop- erly 10 years after the bypass surgery. Vein grafts may become obstructed and, after 5 years, a third or more of them may be completely blocked. In such cases the procedure may need to be repeated.
Coronary angioplasty, also called balloon angioplasty, is performed to open a narrowed or blocked coronary artery. The procedure begins with insertion of a hollow needle into the femoral artery in the leg. A long guide wire is threaded
Coronary Artery Bypass
In this example, two bypasses using replacement blood vessels from other parts of the body have been created to reroute blood around blockages in the right and left coronary arteries.
through the needle and into the arterial system, through the aorta, and into the obstructed coronary artery. A catheter (a thin, ﬂexible tube) with a balloon attached to its tip is threaded over the guide wire and into the obstructed artery. The catheter is positioned so the balloon is at the level of the obstruction. The balloon is then inﬂated and deﬂated several times, for several seconds each time. The inﬂated balloon compresses the plaque against the artery wall, widening the narrowed channel and restoring blood ﬂow. The catheter and guide wire are then withdrawn.
Between 80 and 90 percent of arteries that are treated with angioplasty are opened. In about 20 to 30 percent of cases, the coronary artery becomes obstructed again (called restenosis) within 6 months, often within a few weeks after the procedure. Angioplasty is then repeated. This procedure may be used to successfully control coronary artery disease over the long term.
Stent placement is a newer procedure that has been performed more fre- quently in the past several years. Essentially it is angioplasty, with an additional step. Once the obstructed artery has been opened, a tiny metallic or plastic wire mesh (stent) is placed inside the artery to keep it open. This procedure may reduce the risk of restenosis by half.
Numerous studies have shown that success rates of angioplasty are about the same as those of bypass surgery. Most studies comparing these two procedures are now focusing on economics. Recent studies give the edge to bypass surgery in terms of the cost of treating patients over the long term.