(CABG, Open Heart Surgery, Bypass Surgery)
Coronary artery bypass graft surgery (CABG) is a procedure used to treat coronary artery disease in certain circumstances. Coronary artery disease (CAD) is the narrowing of the coronary arteries (the blood vessels that supply oxygen and nutrients to the heart muscle), caused by a buildup of fatty material within the walls of the arteries. This buildup causes the inside of the arteries to become rough and narrowed, limiting the supply of oxygen-rich blood to the heart muscle.
One way to treat the blocked or narrowed arteries is to bypass the blocked portion of the coronary artery with another piece of blood vessel. Blood vessels, or grafts, used for the bypass procedure may be pieces of a vein taken from the legs or an artery in the chest. One end of the graft is attached above the blockage and the other end is attached below the blockage. Thus, the blood is rerouted around, or bypasses, the blockage through the new graft to reach the heart muscle. This bypass of the blocked coronary artery can be done by performing coronary artery bypass surgery.
Traditionally, in order to bypass the blocked coronary artery in this manner, the chest is opened in the operating room and the heart is stopped for a time so that the surgeon can perform the bypass. In order to open the chest, the breastbone (sternum) is cut in half and spread apart. Once the heart is exposed, tubes are inserted into the heart so that the blood can be pumped through the body during the surgery by a cardiopulmonary bypass machine (heart-lung machine). The bypass machine is necessary to pump blood while the heart is stopped and kept still in order for the surgeon to perform the bypass operation.
While the traditional “open heart” procedure is still performed and often preferred in many situations, newer, less invasive techniques have been developed to bypass blocked coronary arteries. “Off-pump” procedures, in which the heart does not have to be stopped, were developed in the 1990’s. Other minimally-invasive procedures, such as key-hole surgery (performed through very small incisions) and robotic procedures (performed with the aid of a moving mechanical device), increasingly are being used.
Two other surgical improvements for persons undergoing CABG are endoscopic vein harvesting and endoscopic radial artery harvesting. In both of these procedures surgeons use an endoscope (thin surgical tube with a light and camera on the end) to locate blood vessels that will be used for bypassing the blocked coronary arteries. Veins are generally harvested from the inner thigh and calf areas of the legs, while the radial artery is harvested from the wrist.
Traditional (open) approaches involve making long surgical incisions down the inner thigh and/or calf. Research comparing traditional approaches with endoscopic methods indicates that patients generally have fewer complications, less leg pain, and shorter hospital stays with the endoscopic harvesting methods. Some persons, however, may not be eligible for these methods because of other health conditions.
Other related procedures that may be used to assess and/or treat the heart include resting or exercise electrocardiogram (ECG), Holter monitor, signal-averaged ECG, cardiac catheterization, chest x-ray, computed tomography (CT scan) of the chest, echocardiography, electrophysiological studies, magnetic resonance imaging (MRI) of the heart, myocardial perfusion scans, percutaneous transluminal coronary angioplasty (PTCA), radionuclide angiography, and ultrafast CT scan. Please see these procedures for additional information.
To better understand how coronary artery disease affects the heart, a review of basic heart anatomy and function follows.
The heart is basically a pump. The heart is made up of specialized muscle tissue, called the myocardium. The heart's primary function is to pump blood throughout the body, so that the body's tissues can receive oxygen and nutrients and have waste substances taken away.
Like any pump, the heart requires fuel in order to work. The myocardium requires oxygen and nutrients, just like any other tissue in the body. However, the blood that passes through the heart's chambers is only passing through on its trip through the body - this blood does not give oxygen and nutrients to the myocardium. The myocardium receives its oxygen and nutrients from the coronary arteries. The coronary arteries lie on the outside of the heart and supply oxygenated blood to the heart tissue.
When the heart tissue does not receive an adequate blood supply, it cannot function as well as it should. If the myocardium's blood supply is decreased for a length of time, a condition called ischemia may develop. Ischemia can decrease the heart's pumping ability, because the heart muscle is weakened due to a lack of food and oxygen.
For many years, coronary artery disease (CAD) was commonly called "hardening of the arteries" and was not easily treated. However, in the last 30 years, many advances have been made in the diagnosis and treatment of cardiac diseases.
Coronary artery bypass surgery is performed to treat a blockage or narrowing of one or more of the coronary arteries, thus restoring the blood supply to the heart muscle.
Symptoms of coronary artery disease may include, but are not limited to, the following:
Unfortunately, there may be no symptoms of early coronary artery disease, yet the disease will continue to progress until sufficient artery blockage exists to cause symptoms and problems. If the blood supply to the heart muscle continues to decrease as a result of increasing obstruction of a coronary artery, a myocardial infarction, or heart attack, may occur. If the blood flow cannot be restored to the particular area of the heart muscle affected, the tissue dies.
There may be other reasons for your physician to recommend coronary artery bypass surgery.
Possible risks associated with coronary artery bypass graft surgery include, but are not limited to, the following:
If you are pregnant or suspect that you may be pregnant, you should notify your physician. If you are lactating, or breastfeeding, you should notify your physician.
Patients who are allergic to or sensitive to medications, contrasts dyes, iodine, or latex should notify their physician.
There may be other risks depending upon your specific medical condition. Be sure to discuss any concerns with your physician prior to the procedure.
Coronary artery bypass graft surgery requires a stay in a hospital. Procedure may vary depending on your condition and your physician’s practices.
Generally, a coronary artery bypass surgery follows this process:
After the surgery you may be taken to the recovery room before being taken to the intensive care unit (ICU) to be closely monitored. Alternatively, you may be taken directly to the ICU from the operating room. You will be connected to monitors that will constantly display your electrocardiogram (ECG or EKG) tracing, blood pressure, other pressure readings, breathing rate, and your oxygen level. Coronary artery bypass surgery requires an in-hospital stay of several days or longer.
You will most likely have a tube in your throat so that breathing can be assisted with a ventilator (breathing machine) until you are stable enough to breathe on your own. As you continue to wake up from the anesthesia and start to breathe on your own, the breathing machine will be adjusted to allow you to take over more of the breathing. When you are awake enough to breathe completely on your own and you are able to cough, the breathing tube will be removed. The stomach tube will also be removed at this time.
After the breathing tube is out, your nurse will assist you to cough and take deep breaths every two hours. This will be uncomfortable due to soreness, but it is extremely important that you do this in order to keep mucus from collecting in your lungs and possibly causing pneumonia. Your nurse will show you how to hug a pillow tightly against your chest while coughing to help ease the discomfort.
The surgical incision may be tender or sore for several days after a CABG procedure. Take a pain reliever for soreness as recommended by your physician. Aspirin or certain other pain medications may increase the chance of bleeding. Be sure to take only recommended medications.
You may be on special IV drips to help your blood pressure and your heart, and to control any problems with bleeding. As your condition stabilizes, these drips will be gradually decreased and turned off as your condition allows.
Once the breathing and stomach tubes have been removed and your condition has stabilized, you may start liquids to drink. Your diet may be gradually advanced to more solid foods as you are able to tolerate them.
When your physician determines that you are ready, you will be moved from the ICU to a post-surgical nursing unit. Your recovery will continue to progress. Your activity will be gradually increased as you get out of bed and walk around for longer periods of time. Your diet will be advanced to solid foods as you tolerate them.
Arrangements will be made for a follow-up visit with your physician.
Once you are home, it will be important to keep the surgical area clean and dry. Your physician will give you specific bathing instructions. The sutures or surgical staples will be removed during a follow-up office visit, in the even they were not removed before leaving the hospital.
You should not drive until your physician tells you to. Other activity restrictions may apply.
Notify your physician to report any of the following:
Your physician may give you additional or alternate instructions after the procedure, depending on your particular situation.
The content provided here is for informational purposes only, and was not designed to diagnose or treat a health problem or disease, or replace the professional medical advice you receive from your physician. Please consult your physician with any questions or concerns you may have regarding your condition.
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