Coronary Artery Bypass Grafting (CABG), or bypass surgery, is a surgical operation in which the surgeon uses a section of vein, usually from the patient's leg, or an artery from inside the patient's chest, to create a new route for oxygen-rich blood to reach the heart muscle.

The most commonly used vessels are the internal mammary arteries, which are inside the chest wall, or the greater saphenous veins, which are in the leg. These vessels are "spares." Blood flow is usually not affected by removing them. Less often, the radial artery in the arm may be used for a graft. Grafts usually last for 10 to 12 years.

Procedure

One end of the vein or artery is connected to the coronary artery that is blocked or narrowed beyond the blockage or narrowed area. The other end of the vein is connected to the aorta. Usually the other end of the artery is left connected to the main artery from which it branches. By creating this new conduit for blood flow to the heart muscle, the graft is said to "bypass" the narrowed or blocked section of the coronary artery in question. Depending on the number and location of blockages, between one and seven bypasses are performed.

A heart-lung machine is used to circulate and oxygenate the blood while the surgeon works on the stopped heart. The heart is accessed by dividing the patient's sternum with a 10-12" long incision on the patient's chest. After the bypasses are complete, the heart is restarted until it is beating normally, and the patient is removed from the heart-lung machine. A wire sternotomy suture is used to close up the sternum, and sutures or clips are used to close up the chest and leg wounds.

Patient Stay

A patient who undergoes CABG surgery usually stays in the ICU for approximately 2 days, with a total hospital stay of 7-10 days.

Minimally Invasive Direct Coronary Artery Bypass (MIDCAB) is a minimally invasive approach to conventional Coronary Artery Bypass Graft (CABG) surgery. MIDCAB is beating heart surgery, which means that stopping the heart (cardioplegia) is not necessary and a heart-lung machine is not required.

Unlike conventional surgery, which requires a 10"-12" incision to separate the sternum (sternotomy) and places the patient on the heart-lung machine, MIDCAB surgery can be performed through a 3"-5" incision placed between the ribs, or may be done with several small incisions.

MIDCAB surgery results in a faster recovery, fewer complications, and less pain after surgery. It is indicated for use when bypassing one or two coronary arteries. For bypassing three or more arteries, a conventional CABG is indicated.

How do surgeons perform surgery on a beating heart?

One of the greatest challenges in minimally invasive bypass surgery is the difficulty of suturing or "sewing" on a beating heart. If the surgeon chooses to operate on a beating heart, a stabilization system is used to steady only the portion of the heart where the surgeon is operating. A stabilization system avoids use of the heart-lung machine by making it possible for the surgeon to carefully work on the patient's heart while it continues to beat.

Potential Patient Benefits of Minimally Invasive Bypass Surgery

Minimally invasive bypass surgery is believed to have the same beneficial results as conventional bypass surgery--restoring adequate blood flow and normal delivery of oxygen and nutrients to the heart. Minimally invasive bypass surgery, however, has additional advantages related to the ability of the surgeon to work on a beating heart or through smaller incisions.

Shorter length of stay: Patients may experience less pain and may have a better ability to cough and breathe deeply after the operation so they are often discharged from the hospital in 2 to 3 days, compared to the typical 5 to 10 days for conventional CABG surgery.

Faster recovery: Avoidance of the heart-lung machine and the use of smaller incisions may reduce the risks of complications such as stroke and renal failure so that patients can return to their normal activities in 2 weeks rather than the typical 6 to 8 weeks with conventional surgery.

Less bleeding and blood trauma: Any time blood is removed from the body and put into the heart-lung machine, the patient must be put on anticlotting medications or given "blood products". Artificial circuits such as the heart-lung machine can also damage blood cells. These factors may affect the blood's ability to clot after surgery. Avoiding the heart-lung machine can alleviate this blood trauma.

Lower infection rate: A smaller incision means less exposure and handling of tissue, which may reduce the chances of infection.

Available to more patients: Some patients are poor candidates for traditional bypass surgery because their illness is too widespread, their heart is too weak, or because they will not accept blood products. Some patients are able to receive this life-saving surgery through minimally invasive techniques.

Less cost: The cost of minimally invasive cardiac surgery may be approximately 25% less than the cost of conventional surgery.

Heart valve disease occurs when a valve doesn't work right. A valve may not open all the way. Or, a valve may have problems closing. If this happens, blood doesn't move through the heart's chambers the way it should.

Problems with Your Heart Valves

If a valve doesn't open all the way, less blood moves through to the next chamber. If a valve doesn't close tightly, blood may leak backward. These problems may mean that the heart must work harder to pump the same amount of blood. Or, blood may back up in the lungs or body because it's not moving through the heart as it should.

Problems Opening

Stenosis occurs when a valve doesn't open fully. The valve may have become hardened or stiff with calcium deposits or scarring. So, it's hard to push open. Blood has to flow through a smaller opening, so less blood gets through the valve into the next chamber.

Problems Closing

Insufficiency (also called regurgitation) results when the valve doesn't close tightly. The valve's supportive structures may be loose or torn. Or, the valve itself may have stretched or thinned. Blood may then leak back the wrong way through the valve.

Heart Valve Surgery

During heart valve surgery, one or more valves are repaired or replaced. Repair means that the valve is mended to help it work better. Replacement means your diseased valve is removed and a new valve is inserted in its place. Whether a valve will be repaired or replaced can only be decided once surgery has begun. Your surgeon will talk with you about his or her plans for surgery and any other procedures you may need.

Repairing a Valve

During valve repair, a ring may be sewn around the opening of the valve to tighten it. Other parts of the valve may be cut, shortened, separated, or made stronger to help the valve open and close right.

Replacing a Valve

If a valve can't be repaired, it may be replaced with a prosthetic valve. Two kinds of prosthetic heart valves are available:

Mechanical valves are created from man-made materials. Lifetime therapy with an anticoagulant (sometimes called a "blood thinner") is needed when these types of valves are used. This medication prevents blood clots from forming on or around the valve.

Biological (tissue) valves are taken from pig, cow, or human donors. These valves don't last as long as mechanical valves. But when tissue valves are used, long-term use of an anticoagulant often isn't needed.

Your doctor will talk with you about choosing the best valve for you. Factors weighed include your age, your occupation, the size of your valve, how well your heart is working, your heart's rhythm, your ability to take an anticoagulant, and how many new valves you need.

Reaching Your Heart

To get to your heart, one or more incisions must be made in your chest. For minimally invasive valve surgery, these incisions are most often much smaller than those made for traditional valve surgery. One of two types of incisions may be used. Which type your surgeon chooses depends on the location of the valve and the method of surgery used. Your surgeon will talk with you about which incision you will receive.

Stopping Your Heart

During valve surgery, your heart must not beat. To keep your blood flowing, it is passed through a heart-lung machine. This machine gives oxygen to your blood and pumps the blood back through your body. Your surgeon may choose to connect your body to the machine through the vessels in your heart or through vessels in your groin. Once the valve surgery is done, your heart and lungs take over again.

Repairing or Replacing the Valve

To reach the valve, an incision is made in your heart or aorta. If the valve can be mended, the needed repairs are done. If the valve must be replaced, part or all of the damaged valve and its supportive structures may be removed. The right-sized replacement valve is selected, positioned in the valve opening, and sewn firmly into place. The incision in your heart or aorta is closed. Your heart is then started so it beats on its own again.

Angioplasty is a procedure that widens a narrow or obstructed blood vessel using a balloon catheter. It is used to treat atherosclerosis (blood vessel obstructions), and usually performed by an interventional cardiologist, a medical doctor with special training in the treatment of the heart, using invasive catheter-based procedures.

Angioplasty is commonly performed as a minimally-invasive (percutaneous) procedure, where a stent (small mesh tube) is inserted into the blood vessel to keep it open. A possible alternative to heart surgery, it has consistently been shown to reduce symptoms due to coronary artery disease and reduce cardiac ischemia.

The Procedure

1. An introducer needle is inserted into the femoral artery in the leg (sometimes into the radial artery or brachial artery in the arm).
2. A sheath introducer is placed in the opening to keep the artery open and control bleeding.
3. A guide catheter (long, flexible, soft plastic tube) is then pushed through the sheath introducer. Dyes can be injected through the guide catheter into the coronary artery to locate and study the diseased artery using x-ray.
4. After studying the x-ray image, the cardiologist selects the type of balloon catheter and flexible coronary guidewire that will be used.
5. The flexible coronary guidewire with radiopaque plastic tip is then inserted into the guiding catheter and into the coronary artery.
6. Viewing through x-ray imaging monitor, the cardiologist guides the flexible coronary guidewire through the coronary artery to the site of the blockage.
7. When the flexible guidewire reaches the blockage, it is then pushed across the blockage.
8. A hollow-tipped balloon catheter is then inserted, using the flexible guidewire as a pathway to the site of the blockage. At this point, the balloon is still deflated.
9. After the balloon catheter reaches and is pushed inside the blockage, the balloon is then inflated. Inflating the balloon expands the area around it and compresses the plaque buildup (blockage). The inflated balloon also expands the artery wall.
10. A stent (wire mesh tube) sometimes is implanted to keep the artery wall expanded. The stent initially is inserted along with the balloon catheter, expands when the balloon is inflated, and left behind in the expanded position as the balloon catheter is removed.

What are the non-surgical treatment options?

Each year many patients with coronary artery disease will need treatment to restore the flow of blood to the heart. That treatment might include drug therapy, angioplasty or surgical intervention.

Drugs can work to dilate the coronary arteries, enabling more blood to be delivered to the heart tissue. Angioplasty is a procedure where a tiny balloon is inserted into the blocked artery and inflated at the site of a blockage. Inflating the balloon reopens the vessel. The balloon is then deflated and removed. A small frame called a "stent" can also be placed in the artery after angioplasty to ensure that the artery remains open.

What are the disadvantages of these non-surgical treatments?

Drug therapy only treats the symptoms of coronary artery disease. In addition, drugs often have adverse side effects and are not always effective at increasing the blood supply to the heart. Angioplasty is not suited for treatment of all types of blockages and it is only a temporary solution-angioplasty can fail and arteries can become blocked again.