Coronary Artery Disease and Angina

Description

Alternative Names

Coronary Artery Bypass Graft Surgery

Coronary artery bypass graft surgery (CABG) is a good alternative to angioplasty for many patients, but it is very invasive. It involves the following processes:

• The chest is opened and the blood is rerouted through a lung-heart machine.
• The heart is stopped during the procedure.
• Large blood vessels supply the grafts, which are used to reroute the blood. The blood vessel grafts are transplanted in front of and beyond the blocked arteries, so the blood flows through the new vessels around the blockage.
• The standard grafts now use arteries taken from the chest wall. Studies are reporting that with such grafts arteries remain open in 90% of cases after 15 years.
• In general, patients with triple bypass procedures stay in the hospital for five days. Those with one-vessel bypass may be able to go home in three days.

Click the icon to see an illustrated series detailing a heart bypass surgery.

Complications

In spite of the invasive nature of this procedure, in general, elective bypass procedures produce better long-term survival rates than angioplasty, particularly in patients with diabetes and multi-vessel blockage. Overall mortality rates after this procedures ranges from 1% to slightly over 2%. The risk for stroke or heart attack after a bypass operation range from 1.3% to 5%. A 2002 study suggested that giving patients beta-blocker drugs before surgery may reduce complication rate and improve survival rates. Finding a surgeon who performs at least 100 of the procedures a year helps reduce the risk for complications.

Blood clots may form in the new graft, closing it up or narrowing the treated vessel over time. Therapy with aspirin and other anti-clotting drugs help keep the graft open and working properly. For long-term prevention of closure as well as slowing progression of atherosclerosis, aggressive use of cholesterol-lowering drugs may be more beneficial than the standard anti-clotting drugs.

Of some concern are studies reporting a decline in mental function five years after bypass surgery. It is not known, however, if patients with bypass procedures tend to have other higher risk factors for mental decline (being older or sicker than those who choose angioplasty). Long-term studies are underway. Some experts attribute problems leading to brain injuries to the pump used in these procedures. Some early studies suggest that newer procedures that allow the heart to keep beating will reduce the risk, but a 2002 study found no difference.

Minimally Invasive Bypass

Minimally invasive bypass (also called buttonhole or keyhole bypass) surgeries are exciting advances in basic bypass surgery that are currently being tested with good success for patients with disease in single vessels. They are even being investigated for multiple vessels.

• One variation of minimally invasive bypass uses a four-inch incision, and the surgeon works on the front of the heart while it is beating slowly. To date, there have been no differences in cardiac events or later mental complications between this so-called off-pump procedure and the standard bypass procedure.
• In another variation, the heart is stopped, and the patient is put on a machine that reroutes the blood through a device that keeps it oxygenated. Fiberoptic scopes and instruments are passed through a number of finger-sized incisions and the surgeon works on all sides of the heart guided by a video image from a tiny camera inserted through a four-inch incision.
• Some advanced heart centers now employ robotic systems, which allow the surgeon to perform extremely delicate maneuvers on tiny vessels through pencil-size incisions. They are not yet used for the whole bypass process.

Eventually minimally invasive bypass procedures may prove to be less expensive, require a shorter hospital stay, and have fewer complications than conventional coronary artery bypass surgery--or even angioplasty. To date, however, they are experimental and are performed only in a few medical centers for select candidates. Long term-success rates are unknown.