What is coronary artery bypass grafting (CABG)?
Coronary artery bypass grafting (CABG) is a procedure used to treat coronary artery disease (CAD) and improve blood flow to the heart. CABG is also known as bypass surgery, coronary artery bypass surgery and heart bypass surgery. For more information, visit the Coronary Artery Bypass Surgery for Coronary Artery Disease page in our Health Library.
During the CABG procedure, a healthy artery or vein is taken from another part of the body and joined, or grafted, to the obstructed coronary artery. The grafted artery or vein sidesteps (bypasses) the blocked portion of the coronary artery, allowing the new channel to detour oxygen-rich blood to the heart muscle.
Who needs coronary artery bypass grafting?
CABG is typically performed only on patients with severe blockages in the large coronary arteries. Based on a number of factors, your doctor will decide if you are a candidate for CABG. Determining factors include presence and intensity of CAD symptoms, as well as the location of plaque buildup. In certain instances, such as during, or in case of an imminent heart attack, CABG may be performed on an emergency basis.
To decide whether CABG is necessary, your doctor will evaluate the state of your cardiovascular system, focusing on your heart, lungs, and pulse. Your doctor will ask about any symptoms you might have, including chest pain or shortness of breath, as well as the length, frequency, and severity of symptoms. To determine which arteries are blocked, the extent of blockage, and whether there is any heart damage, medical tests like EKG, stress test, echocardiogram and angiography will be performed.
Most people with less severe types of CAD are treated with regiments such as lifestyle changes, medicines, and angioplasty, first. For patients who have limited success with the alternative choices, CABG is an effective and viable option.
What to expect before coronary artery bypass grafting?
Your doctor might order a number of tests before your CABG procedure. These may include blood tests, EKG, echocardiogram, chest x ray, cardiac catheterization, and angiography.
You will receive detailed instructions from your doctor on how to prepare for CABG surgery. Instructions will include information on what you can eat or drink, what medicines you can take, and what activities to stop (ex: smoking). Most patients are admitted to the hospital on the same day as the surgery.
What to expect during coronary artery bypass grafting?
A diverse team of experts is involved in the performance of coronary artery bypass grafting procedure. A cardiothoracic surgeon performs the surgery with support from an anesthesiologist, physician assistant, perfusionist (heart-lung machine specialist), as well as other surgeons, and nurses.
CABG procedures require general anesthesia and last typically 3 to 5 hours, depending on the number of arteries being bypassed. Before surgery, anesthesia is administered to put you to sleep. During the length of the procedure, the anesthesiologist monitors your heartbeat, blood pressure, oxygen levels, and breathing. A breathing tube, placed in your lungs through your throat, and connected to a ventilator, helps you breathe.
What are different types of coronary artery bypass grafting?
There are several distinct types of CABG. Coronary artery bypass grafting procedures range from traditional methods to less invasive surgeries to a robot-assisted technique that allows the surgeon to perform the operation with remotely controlled surgical instruments.
In deciding on the best match between the patient and the type of coronary bypass procedure, the surgeon considers a number of factors. Factors include patient's age, build, weight, as well as the location and magnitude of plaque buildup. Presence of other illnesses, such as lung disease or hardened arteries, is also considered.
Interestingly, for many patients with more acute conditions, traditional heart surgery may be the safest option.
How is traditional coronary artery bypass grafting performed?
Traditional coronary bypass surgery involves an incision through the breastbone and the use of a heart-lung machine. The chest bone is cut and ribcage opened so that the surgeon can get to the heart. During this time, the heart is temporarily stopped while a heart-lung machine circulates oxygen-rich blood throughout your body.
Once grafting is completed, your heart is restarted with mild electric shocks. You are disconnected from the heart-lung machine, and the fluid drainage tubes are inserted into your chest. The surgeon then uses wires to enclose your chest bone and stitches or staples to close the skin incision. Once you are able to breathe on your own, the breathing tube is removed.
How is off-pump coronary artery bypass grafting performed?
Off-pump coronary artery bypass grafting can be used to bypass any of the coronary arteries. During this procedure the heart isn’t stopped, nor is a heart-lung machine utilized. Instead, the part of the heart where grafting is taking place is steadied with a mechanical device. As a result, off-pump coronary artery bypass grafting is also called beating heart bypass grafting.
Because a heart-lung machine is not used during off-pump CABG, fewer complications tend to occur. This is especially true in people who had suffered a stroke or "mini-strokes" in the past, who are over 70 years of age, or patients afflicted with diabetes, lung disease, or kidney disease. Other advantages of off-pump CABG include decreased bleeding during surgery, smaller likelihood of infection and other complications and faster recovery.
How is minimally invasive direct coronary artery bypass grafting performed?
There are several types of minimally invasive direct coronary artery bypass (MIDCAB) grafting. These procedures vary from traditional bypass surgery in that, rather than requiring the opening of the chest bone to get to the heart, they only involve small incisions.
- MIDCAB procedure is applied when only one or two coronary arteries are going to be bypassed. A number of small incisions are made between your ribs, on the left side of your chest, or directly over the artery to be bypassed. The incisions are usually about 3 inches long, as opposed to incisions made in traditional CABG which are at least 6 to 8 inches long. Most frequently, the left internal mammary artery is used for the graft. A heart-lung machine isn't used during this procedure.
- Port-access coronary artery bypass procedure is performed through small incisions, or ports, made in your chest. Artery or vein grafts are used. A heart-lung machine is used during this procedure.
- Robot-assisted technique is a procedure that allows for even smaller, keyhole-sized incisions. A small video camera, inserted through one incision, shows the patient’s heart and allows the surgeon to perform the operation with remotely controlled surgical instruments. The heart-lung machine is sometimes used during this procedure.
Benefits of minimally invasive CABG include smaller incisions, less noticeable scars, shorter recovery and hospital time, reduced bleeding, decreased chance for infection, and less pain.
What to expect after coronary artery bypass grafting?
After your coronary artery bypass grafting procedure, you will generally spend 1 to 2 days in an intensive care unit. Your heart rate and blood pressure will be closely monitored and you might be given intravenous medicines to regulate your blood circulation and blood pressure. When your condition has stabilized, you will be moved to a less intensive care area of the hospital for 3 to 5 days of monitoring.
For your recovery time at home, your doctor will provide you with detailed instructions. These will include guidance on caring for your healing incisions, recognizing signs of infection or other complications and knowing when to call the doctor immediately.
Instructions will also be provided on how to manage common surgery after-effects which generally disappear within 4 to 6 weeks after the operation. After-effects may involve one or more of the following symptoms:
- Irritation or itching from healing incisions
- Swelling of the area where an artery or vein was taken for grafting
- Muscle ache or tightness in the shoulders and upper back
- Fatigue, mood swings, or depression
- Difficulty sleeping
- Loss of appetite
- Chest pain around the site of the chest bone incision (this is more frequent with the traditional surgery)
Complete recovery from traditional CABG may take 6 to 12 weeks or longer. Nontraditional CABG patients usually have a shorter recovery time.
You will receive instructions from your doctor on when to resume regular physical activities. Although time-frames vary between patients, most people can resume sexual activity within 4 weeks and driving after 3 to 8 weeks. Most patients return to work after 6 weeks, unless their job involves strenuous physical labor. Some people may be advised to consider changing to less physically demanding type of work, permanently; others, to work a reduced schedule at first.
What kind of ongoing care should I expect after coronary artery bypass grafting?
Ongoing care after CABG will include intermittent checkups with doctors. Tests (EKG, stress testing, and echocardiogram) may be performed during these visits, to see how your heart is functioning.
CABG is not a cure for coronary artery disease so you and your doctor may look at other options for staying healthy and reducing the chances of CAD worsening. Options may include developing a long term care plan that involves lifestyle changes like quitting smoking, following a healthy diet rich in fruits and vegetables, getting regular exercise, and managing stress.
Some patients might be referred by their doctor to a cardiac rehabilitation (rehab) program. After surgery, rehab programs can bolster you strength and energy through exercise training, and help you return faster to your daily routine. Also, through supervised physical activity and education, rehabilitation will guide you in pursuing healthier lifestyle choices that considerably reduce the risks of future heart problems.
Taking medicines as prescribed by your doctor is another essential component of post-surgery care. Medicines may be prescribed to manage pain through recovery; to lower cholesterol or blood pressure; to reduce the chance of developing blood clots; to treat diabetes; to alleviate depression.
What are the risks of coronary artery bypass grafting?
Even though complications from coronary artery bypass grafting are uncommon, risk is a part of every surgical procedure. Potential risks include wound infection and bleeding, adverse reactions to anesthesia, fever, pain, stroke, heart attack, or even death.
Some patients may develop a fever 1 to 6 weeks after surgery. This can be due to inflammation of the lung and heart sac, after surgeries that involve cutting through the pericardium (the outer covering of the heart). Symptoms range from chest pain to irritability and decreased appetite. This is usually a mild, self-limited illness, but a small number of patients may develop fluid buildup around the heart that necessitates further treatment.
Use of the heart-lung machine can also lead to complications. Some patients have experienced side effects like memory loss, difficulty concentrating or thinking clearly. These developments are more likely to occur in older people, patients with high blood pressure or lung disease, or those who consume excessive amounts of alcohol. These reactions mostly disappear several months after surgery.
The heart-lung machine can also raise the risk of blood clots. Clots can form in your blood vessels, then travel to the brain, lungs or other parts of the body, blocking blood flow and causing a stroke or other problems. Latest technical enhancements in heart-lung machines are lowering the risks of blood clots.
In most cases, the risk of complications are higher when CABG is done in an emergency situation (ex: if performed during a heart attack), if you are over 70 years old, or if you have a history of smoking. Your risks also rise if you have other diseases or conditions such as diabetes, kidney disease, lung disease, or peripheral vascular disease.
What results can I expect at the University of Michigan's Frankel Cardiovascular Center?
Coronary artery bypass grafting is the most common type of open-heart surgery in the US, with nearly 400,000 procedures completed each year. At the University of Michigan, we perform nearly 300 CABG surgeries every year.
CABG surgery candidates usually have excellent results. Symptoms are significantly improved in 85 percent of patients; there is a reduced chance of future heart attacks, and a decreased risk of dying within 10 years following surgery.
Repeat CABG surgery may be needed in patients where grafted arteries or veins become obstructed again, or if new blockages develop in arteries that weren't blocked before. However, by taking prescribed medicines and maintaining an active and healthy lifestyle, you can reduce the chances of a graft becoming blocked.