DISCLAIMER: THIS PAGE CONTAINS A GENERAL EDUCATIONAL DISCUSSION ON THE ABOVE TOPIC. IT IS NOT HEALTH ADVICE AND SHOULD NOT BE CONSTRUED AS SUCH. YOU SHOULD NEVER RELY UPON THE INFORMATION GIVEN HERE. YOUR PARTICULAR CIRCUMSTANCES MAY WELL REQUIRE AN ENTIRELY DIFFERENT APPROACH. YOU SHOULD NOT MAKE ANY CHANGES IN YOUR MEDICATIONS, DIET, ACTIVITY, LIFESTYLE, ETC. WITHOUT FIRST CONSULTING A LICENSED PHYSICIAN IN YOUR AREA.
Coronary artery bypass surgery is a major surgical procedure performed under general anesthesia that has been in existence since 1967. Of all the treatments for coronary artery disease, it is the most effective for relief of angina. In certain situations, it has also been proven to prolong patient survival.
In the early 1980s, researchers compared patients who underwent bypass surgery with those treated medically during the 1970s. They found that, in retrospect, many of the patients treated with a bypass would have done just as well with medications. Based on these results, doctors have now refined their approach. Nowadays, an unnecessarily performed bypass is quite rare. Bypass operations are recommended when:
Symptoms cannot be controlled with medications or transcatheter revascularization.
A transcatheter revascularization is technically impossible to do.
Restenosis keeps reoccurring after a transcatheter revascularization.
There are multiple blockages and the patient is a diabetic.
There are multiple blockages and the patient prefers bypass surgery and getting the entire problem over with rather than doing transcatheter revascularization and risk needing repeat procedures in the near future for restenosis.
The patient's characteristics (number and location of blockages, strength of the heart muscle, exercise tolerance) indicate that their survival will be prolonged by bypass surgery.
The term "bypass" refers to the fact that the surgeon bypasses, or creates a detour around, the sites of narrowing or blockage in the artery. The surgeon takes a blood vessel from somewhere else in the body that the body can spare. One end of this vessel is connected to the aorta-the main blood vessel that the heart pumps blood into and then gives blood to the rest of the body-at the point where it connects to the heart. This is where the native coronary arteries originate as well. The other end of this bypass is connected to the narrowed artery beyond the site of narrowing.
The vessels used for the bypass are most commonly veins in the legs although arm veins are used on occasion as well. Surgeons are increasingly using arteries such as the artery that runs along the inside of the chest wall or an artery in the arm since these seem to last longer than vein grafts. A chest incision is made vertically through the middle of the breast bone. It extends throughout the length of the breastbone.
The traditional method of doing this operation involves stopping the heart from beating. The patient is put on "cardiopulmonary bypass" (another use of the word bypass). The blood that normally returns to the heart is sent through tubes to an oxygenator ( a heart-lung machine) which then pumps the oxygenated blood back through tubes into the aorta. This makes sure the body gets enough blood flow and oxygen while the heart is not beating. The heart itself is bathed in a"cardioplegic solution" to lower its metabolism so it can tolerate not receiving blood during the procedure. Once the bypass grafts are finished, the heart is given an electrical shock and it starts beating again. These operations generally last anywhere from 2 to 5 hours.
Surgeons can also do some bypass operations on the beating heart without going on cardiopulmonary bypass. This is technically more demanding but avoids the stress to the patient's system caused by cardiopulmonary bypass and the heart-lung machine. The "off-pump" technique is more more likely to be done when there are only a limited number of vessels to bypass, the vessels are technically easy to bypass and the patient is felt to be at higher risk of complications from the heart-lung machine. Not every patient is a candidate for this technique. This approach decreases the need for blood transfusions, and reduces the rate of complications such as abnormal heart rhythms, low blood pressure, strokes, kidney problems and chest infections. It also reduces injury to the heart, brain, and the blood clotting system. These benefits translate into shorter stays in the intensive care unit and the hospital and less cost. Total patient survival may be improved when appropriate patients are selected for this procedure. However, concern has been raised that the off-pump technique may result in a higher rate of the bypass grafts narrowing soon after the operation and that it may not allow the surgeon to bypass all vessels that require a bypass.
After the surgery, the patient is brought to the ICU. There, they wake up and the breathing tube is removed from their mouth. Various other IVs and drainage tubes are removed over the next 48 hours. Patients are often eating on their own within 24 hours and on their feet within 48 hours. They may go home as early as the fourth postoperative day although longer stays are not uncommon.
It is normal to feel weak and short of breath after a bypass. These symptoms resolve over time. By the time of hospital discharge, the patient is able to walk on their own. They will gradually return to full strength over the next 6 to 8 weeks. Enrollment in a cardiac rehabilitation program is quite effective at restoring patient's strength. Pain from the healing incisions is usually not severe and easily controlled with medications. Patients usually have to wait about 6 weeks before they are allowed to drive and return to work.
Nothing is perfect in life and bypass grafts are no exception. They can develop their own blockages with time. Narrowed bypass grafts can be treated by transcatheter techniques or a repeat bypass operation. After 10 years, about 40% of vein grafts are narrowed while only 2% of arterial grafts are narrowed.
Related topic: Minimally Invasive Open Heart Surgery
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