Heart Bypass Surgery
• What Is A Heart Bypass?
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|What Is A Heart Bypass?
Coronary artery bypass surgery is a major surgical procedure which is used for treating blockages in the arteries which supply the heart with blood. It involves taking a blood vessel from another part of the body and grafting it onto the blocked coronary (heart) artery. This means a new route for blood to flow is created (the blockage is bypassed) and adequate blood flow can be restored to the heart. The operation is sometimes referred to as CABG (coronary artery bypass grafting pronounced cabbage), or CAB (coronary artery bypass). Arteries can become blocked over time by the buildup of cholesterol, fats and other substances in a process called atherosclerosis. When the arteries become diseased in this way, it is known as coronary heart disease (CHD). Symptoms of coronary heart disease include angina attacks and chest pain. If an artery becomes completely blocked it causes a heart attack. About 427,000 bypasses are performed every year in the United States, primarily to help reduce a person's risk of having a heart attack.
Bypass surgery is only considered where medication and/or coronary angioplasty (which is far less invasive) will not be sufficient to restore adequate blood flow to the heart. Instances include:
chest pain and angina. Women are more likely to experience angina pain and men are more likely to feel chest pain. However, CHD can be a silent disease (particularly in those with diabetes) and the first sign may be a heart attack (see Heart Attacks in Women). If your doctor suspects you have the disease, and you have significant heart disease risk factors (such as high blood pressure and a strong family history) then he will send you for heart disease testing. A diagnosis of coronary heart disease is only possible by heart catheterization (specifically coronary angiography) which involves inserting a small tube directly into the arteries so that the doctor can physically view any blockages. Before this a stress test is usually performed by electrocardiogram (ECG) or echocardiography. An exercise stress test or any of the following tests may be used:
Chemical Stress Test
Nuclear Heart Scan
As most bypass surgeries are elective you will have time to discuss the pros and cons, and any possible alternatives with your doctor. Once you have made the decision to go ahead, do be sure to bring a list of all the medications you are taking when you arrive at hospital for your operation. As the day of the surgery approaches mention any changes in your health to your doctor, including colds, flus and runny noses. Even a minor illness can affect the chances of recovery. You will need to fast (no food or water) after midnight before the surgery to prevent vomiting during the procedure. If you do eat or drink something, be sure to tell the nurse. If you need to take some water with medications, check this with your doctor first. On the morning of surgery, or a day or two beforehand you will undergo an ECG and chest X-ray. Blood and urine samples may also be taken.
The traditional heart bypass technique involves making an incision in the chest from the breastbone to the sternum (called a median sternotomy). The chest wall is opened to allow access to the heart. At the same time, the patient is connected to a cardiopulmonary machine which functions as an artificial heart and lung. The heart is stopped using a chemical mixture for the duration of the procedure so that it is not full of blood while the surgeon works. Once the surgery is over, the machine is stopped and the heart takes over again. A bypass can be performed using various types of vessels. The surgeon might for example remove the saphenous vein, which is a long vein in the leg or the radial artery which is a vein in the arm. Neither is crucial to blood flow in those areas and so can be safely removed. One end of the removed vein is stitched to the aorta (the main artery which leaves the heart) and the other end is grafted onto the affected artery just after the blockage. In effect a new artery has been created which bypasses the blocked one. Sometimes a surgeon will create a bypass with one or both of the internal mammary arteries (now called the internal thoracic arteries, ITA). These are located under the chest wall and originate from the aorta. This means only one end needs to be detached and grafted onto the blocked artery. The tissue areas that the ITAs used to supply can be supplied adequately by other remaining arteries. ITAs tend to be used more frequently nowadays because they have less of a tendency to form new blockages after surgery. Once all is in place the doctor will perform an angiogram to check for any internal leakages. Then the surgeon restarts the heart by administering an electric shock. The cardiopulmonary is switched off.
What Causes Coronary Heart Disease? Read about Causes of CHD.
Newer techniques have been developed which allow the surgeon to operate on a beating heart, eliminating the need for the heart-lung cardiopulmonary machine. This is known as 'beating heart surgery' or 'off pump bypass surgery'. This approach is much more difficult and cannot be used on all blockages. Furthermore it requires a highly skilled surgeon. The advantage is that it reduces the risks of complications associated with using heart-lung machines. A minimally invasive heart surgery procedure is another possible technique which leaves a much smaller scar on the chest (2 or 3 inches instead of 8 inches associated with traditional CABG). It results in less bleeding which lowers the risk of post-surgery infection and speeds up recovery time.
The first 1 to 3 days are likely to be spent in intensive care. Medical staff will monitor the patient's heart on a regular basis. A breathing tube will be inserted for several hours after the operation and attached to a ventilator. Drainage tubes will be inserted into the chest to remove the buildup of any fluid or blood. A catheter will be inserted in the neck so that the heart and pressure can be monitored. The patient will be attached to a temporary pacemaker device and fluids will be administered by IV to keep them hydrated and to give pain-relief drugs. Some hospitals allow the patient to control their own administration of pain medications. Studies show that patients who administer their own drugs tend to use less and recover faster. The breathing tube is removed after a few hours and the patient will be able to walk around within 1 or 2 days. When the doctor is happy with their progress, the patient will be able to leave intensive care and the remaining tubes will be removed. They usually remain in hospital for 5 to 7 days in total.
Recovery At Home
Most patients recover within 4 to 6 weeks at home, but a full recovery may take up to 6 months. Doctors normally advise patients to gradually work their way back up to normal activities. See also: Living With Heart Disease.
The long-term results of bypass operations are very successful. 90 percent of people report improvement in angina symptoms and 50 percent remain symptom-free for at least 5 years. Many more experience an increase in energy levels after recovery. Very often they will not realize how slowed they had become before surgery. In some high-risk groups, the surgery may extend their life expectancy (although this is still debatable). After a few weeks, most people return to work and activities they enjoyed before surgery. Yet bypass surgery is not a cure for CHD or atherosclerosis. Blockages can start appear in other arteries or they can form in different parts of the same artery (or arteries) which were operated on. About 4 out of 5 people who have bypasses display signs of new blockages within 10 years. Also, statistics show that women are twice as likely to die during or soon after surgery than men. This may be because they tend to be older on average (by 10 to 15 years) when it is performed. This is one reason why the operation is offered less to women.
If one artery is bypassed, this is known as a single bypass. Triple, quadruple and quintuple bypasses similarly refer to the number of heart arteries that are bypassed during the operation. It is worth noting that just because one patient undergoes a triple bypass and another has a single bypass, one is not necessarily sicker than the other. It may just be that the person who has a single bypass has fewer 'accessible' target arteries. For example their blocked arteries may be too small to tackle by surgery or they may be so blocked (calcified) that the blockage runs the extent of the artery so a bypass will have no useful effect.
Any surgery which requires opening the chest wall to operate on the heart is categorized as open heart surgery. CABG is the most common type of open heart procedure, although it may also be used for fixing congenital heart defects or holes in the heart.
Bleeding or infection.
Anemia is common but disappears of its own accord.
Urinary tract infections.
Stroke in Women and men.
Heart attack during or after surgery.
Heart arrhythmia may appear after surgery but this can be treated with medication or the installation of a pacemaker.
The most common alternative to CABG is coronary angioplasty. Angioplasty is suitable in certain situations however research shows that CABG is usually more effective in people over 65 years and for those with diabetes.
|Related Articles on Open Heart Surgery
For more about cardio-health, see the following:
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